AUCTORES
Globalize your Research
Research Article | DOI: https://doi.org/10.31579/2690-1919/498
1Département de Cardiologie, Centre Hospitalier Universitaire Brabois, Nancy, France
2Université de Lorraine, 54000, Nancy, France
3Department of Prevention and Security of Care, Sahloul University Hospital, Faculty of Medicine of Sousse, University of Sousse, Tunisia
*Corresponding Author: Hadrien Pichené. Department of Cardiology, university Hospital Nancy, rue du Morvan 54511 Vandoeuvre-les-Nancy, France.
Citation: Hadrien Pichené, Mahmoud C. Bouhlel, Hela Ghali, Pierre A. Metzdorf, Jeanne Varlot, et al, (2025), Deferred Versus Immediate Stenting for Treatment of Acute Myocardial Infarction: a Retrospective Matched Evaluation, J Clinical Research and Reports, 19(3); DOI:10.31579/2690-1919/498
Copyright: © 2025, Hadrien Pichené. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received: 01 February 2025 | Accepted: 22 February 2025 | Published: 31 March 2025
Keywords: venous malformation; limb dysfunction; treatment status; sclerotherapy; surgical treatment; pharmacotherapy
Background: In myocardial infarction, despite successful treatment by primary percutaneous coronary intervention with stent implantation, unsuccessful reperfusion may occur. The aim of this study was to assess clinical outcomes of a deferred stenting strategy and to determine criteria benefitting most of this strategy.
Methods: This mono-centric retrospective study included all patients managed by deferred stenting for AMI between 2014 and 2020 (n = 80). This group was matched in 2:1 with patients treated by immediate stenting (n = 160). The primary endpoint was a composite of major adverse cardiac event at 1 and 2 years follow up. Secondary endpoints included angiographic and clinical parameters. Further patients were stratified according to conditions retained favorable to a deferred stenting strategy.
Results: The primary endpoint occurred in 26 (16%) patients in the IS group and in 21 (26%) in the DS group at 2 years follow-up. (OR 0.55 [0.28 – 1.05]; P = 0.07). No significant differences were found in intra-hospital outcome as well as LVEF at a median follow up of 36 months. A significant difference was observed in the subgroup of patients with lack of collaterals and with short ischemia time, favoring immediate stenting (6 [37.5%] vs 2 [6.2%] ; OR 0.11; P = 0.01).
Conclusion: In patients with AMI differate stent implantation does not reduce occurrence of MACE compared with conventional strategy up to 2 years follow-up. Stratified analysis suggests that deferred stenting should be avoided in absence of collaterals combined with an early AMI presentation.
Acute myocardial infarction (AMI) is worldwide a significant cause of morbidity and mortality.(1) Despite advancements in medical therapy and reperfusion strategies, AMI continues to have negative effects on patient outcomes, such as reinfarction and heart failure and engendering an important socio-economical burden.(2) Further recent efforts to improve prognosis post-AMI through different revascularization strategies have not translated into clinical benefits.(3–5) Primary percutaneous intervention (PCI) with stent implantation, compared with balloon angioplasty alone, has been shown to prevent early reocclusion and reduce the need for subsequent revascularization of the target lesion. Although the mortality benefit of this strategy has not been well established, it is currently the standard treatment for patients with acute ST-segment elevation myocardial infarction (STEMI).(5,6) However, in some patients stenting in the presence of a significant thrombus burden at the culprit lesion can compromise coronary flow by distal embolization and obstruction of the microcirculation. Thus, despite obtaining a patent epicardial vessel, the impaired myocardial reperfusion is increasing the risk of myocardial injury, predisposing to heart failure and hampering prognosis.(7,8)
Various strategies for removing thrombus from the culprit lesion, such as thrombectomy or distal protection devices, have been evaluated in randomized trials with inconsistent results, while adjuvant pharmacological treatment or pre-treatment seemed more promising.(9,10) Advances in dual antiplatelet therapy have significantly reduced the rates of subacute coronary re-occlusion after PTCA in STEMI patients.(11) Further pre-treatment using a combination of anti-thrombin agents and oral bi-anti-platelet therapy has also led to a reconsideration of immediate stenting and has opened the way of stenting after resolution of the acute thrombotic environment. This delayed stenting approach consists of a minimalistic strategy of immediate mechanical intervention - proposed for the first time by Isaaz et al.(12) - enabling coronary reperfusion with minimal damage to the coronary artery and minimizing the risk of distal embolization. The stent may be implanted when the thrombotic load has significantly regressed after a time-period of a combination therapy including an anti-thrombin agent and an oral dual antiplatelet therapy, with or without GPIIb/IIIa blockade, to minimize the occurrence of no-reflow after stenting.(8)
This strategy has been the subject of five randomized trials (3,13–16), without succeeding to demonstrate a clinical benefit in an unselected patient population presenting with acute MI, despite initially promising results of observational series evaluating myocardial perfusion, left systolic function as well as adverse cardiac events.(17–19) Taking into account the results of Souteyrand et al.(20) showing a regression of the thrombotic load within 7 days of myocardial infarction, as well as those of Sianos et al.(21) showing that improved myocardial reperfusion following primary PCI correlates with low thrombotic load on initial angiography, we hypothesize that a deferred stenting strategy would be mostly beneficial in a selected patient population with a high thrombotic burden, at high risk of micro-vascular obstruction, and following a coherent anti-thrombotic protocol.
Patient population
In this monocentric retrospective study all patients hospitalized for acute myocardial infarction (AMI), treated by primary PCI without stent deployment and followed by a second coronary angiogram within 30 days between January 2014 and December 2020 were pre-selected from the institutional database. Prior inclusion all patients’ histories and coronary angiographies were reviewed to confirm a two-stage treatment strategy of AMI. Patients were matched 1:2 with AMI patients who had undergone primary PCI with immediate stenting. The matching process included a two step-procedure a first matching according to gender, age, culprit vessel, coronary status, TIMI flow and a second matching according to ischemic time and Killip class (described in the appendix). Exclusion criteria for both groups were pre-hospital cardiac arrest, cardiogenic shock on admission, fibrinolytic therapy, an intra-stent event, a type C or greater dissection on initial presentation, a suspected embolic origin of acute coronary syndrome or indications for emergency cardiovascular surgery. AMI was defined as symptoms consistent with myocardial ischemia associated with at least one of the following criteria: 1 mm of ST elevation or depression in two contiguous leads, or a raised troponin T or I level on blood sample.(22)
Sub-group stratification
The study population was also stratified according to the criteria: (1) complete application of the anti-thrombotic protocol, and (2) most favorable angiographic and clinical conditions for a deferred stenting strategy.
The complete anti-thrombotic protocol was defined by a curative anticoagulation in association with a bi-antiplatelet therapy for at least 5 days prior to the second coronary angiography. Most favorable condition was definite as a complete antithrombotic protocol and angiographic collaterals of at least Rentrop ≥ 1 distal to the culprit lesion on the initial angiography combined with an ischemia time of > 6 h (sub-group 1). Sub-group 2 had a complete anti-thrombotic protocol, no collaterals or an ischemia time <6h>1 and ischemia time > 6h. Most unfavorable condition was defined as an incomplete anti-thrombotic protocol, no collaterals and an ischemia time <6h>
The stratification according to these two criteria resulted in a 2 by 2 contingency table and thus 4 subgroups.
Endpoints
The primary endpoint was the composite of overall mortality, or recurrent myocardial infarction, target lesion revascularization, stroke or re-hospitalization for heart failure (MACCE) at 2 years after the index AMI. Secondary endpoints included: MACCE at 1 year, MACCE without stroke (MACE) at 1 and 2 years, intra-hospital clinical outcomes, angiographic results at the end of procedure (including TIMI flow grade, myocardial blush grade (MBG) (23) and distal embolization and procedural variables.
Intra-hospital clinical outcomes included biomarker-levels (CPK value measured on patient admission and at 24 hours), LVEF on admission, acute renal failure, hemorrhagic complications, stroke, need for urgent revascularization, recurrence of myocardial infarction and mortality during the intra-hospital period. Renal failure was defined as a grade 2 according to the KDIGO classification (24) and consisted of an increase in plasma creatinine of > 2 times its previous value or the appearance of oliguria (<0> 12 hours. Hemorrhagic complication was defined as TIMI major or minor bleeding that was unrelated to coronary-artery by- pass graft (CABG) surgery.(25) Angiographic analysis is described in the appendix.
Data collection and follow up
The clinical endpoints were collected via the computerized software (DxCare, Dedalus, France) of the University Hospital of Nancy, via the medical correspondence of peripheral hospitals. For each patient latest clinical history, LVEF, percentage of myocardial necrosis as obtained by functional ischemic test were collected. Baseline LVEF was performed within 24 months after inclusion. Re-hospitalization for follow-up coronary angiography and target lesion revascularization, for heart failure, re-infarction or stroke were monitored. Mortality was assessed by consulting two nationwide dedicated websites.
Data are represented as number and percentage for categorical variables, and mean ±standard deviation or median and interquartile range [IQR] for quantitative variables [25th percentile - 75th percentile]. The Kolmogorov-Smornov test was performed in order to evaluate variables distribution. Chi square test or Fisher's exact test were used to compare categorical variables, and Student t-test or Mann-Whitney U test to compare quantitative variables. Significant p value was set at 0.05. Statistical analysis was performed using SPSS ver. 25.0 (IBM, Chicago, IL, USA).
At the University Hospital of Nancy between January 2014 and December 2020 80 patients were treated for AMI with a deferred stenting strategy (DS-group) and all consecutive patients were included in this study. In the same time period a total of 2621 patients underwent primary PCI with immediate stenting. The flow-chart of the included 160 matched patients with immediate stenting (IS-group) is described in Figure 1.
Deferred stenting (n = 80) N(%) | Immediate stenting (n = 160) N(%) | P
| ||
| Male sex | 58 (72) | 116 (72) | 1 | |
| Age, mean (standard deviation) | 61.8 (14.2) | 61.8 (13.8) | 0.98 | |
Body-mass index (kg/m2) Median [IQR] | 26 [23.6 – 30.4] | 26.5 [24.3 – 29.8] | 0.56 | |
| Diabetes mellitus | 11 (14) | 22 (14) | 1 | |
| Hypertension | 40 (50) | 81 (51) | 0.93 | |
| Hypercholesterolemia | 25 (32) | 53 (33) | 0.82 | |
| History of smoking | 49 (61) | 96 (60) | 0.85 | |
| Current smoker | 39 (49) | 75 (47) | 0.78 | |
| Premature coronary artery disease in first-degree relative | 9 (11) | 21 (13) | 0.68 | |
| Previous myocardial infarction | 4 (5) | 11 (6.9) | 0.57 | |
| Previous coronary revascularization | 5 (6.2) | 8 (5) | 0.76 | |
| Previous stroke | 0 (0) | 2 (1.2) | 0.55 | |
| Peripheral-artery disease | 1 (1.2) | 2 (1.2) | 1 | |
| Chronic renal insufficiency | 6 (7.5) | 10 (6.2) | 0.71 | |
Creatinin clearance (ml/min) Median [IQR] | 88 [73-100] | 90 [79- 90] | 0.57 | |
| Chronic obstructive bronchopathy | 4 (5) | 10 (6.2) | 0.78 | |
| Hemoglobin (g/dl), mean (standard deviation) | 13.9 (2.05) | 14.5 (1.67) | 0.02 | |
| STEMI | 71 (89) | 130 (81) | 0.14 | |
| Killip class | 1 | 74 (92) | 153 (96) | 0.42 |
| 2 | 4 (5) | 6 (3.8) | - | |
| 3 | 2 (2.5) | 1 (0.62) | - | |
| Class of delay to treatment | < 6h> | 34 (42) | 71 (44) | 0.99 - - - - |
| 6-11h | 19 (24) | 36 (22) | ||
| 12-24h | 13 (16) | 25 (16) | ||
| > 24h | 14 (18) | 28 (18) | ||
| Delay to treatment | 9.00 [4.00 - 14.7] | 7.00 [3.00 - 15.0] | 0.58 |
There were no significant differences between the DS-group and IS-group in terms of baseline demographic characteristics and clinical presentation except for hemoglobin-levels on admission, which were higher in the IS-group (Table 1). Of the overall population, 72% were male and the average age was 61.8 years. On admission 84% presented a STEMI with a Killip class 1 in 94% of the cases. Median ischemic time was 8 hours and 57% of the patients were managed with an ischemia delay of more than 6 hours. The baseline angiographic data are summarized in Table 2 and were significatively different between the two groups: calcification and thrombotic burden were higher in the DS-group in which a thrombotic load was observed in 100% of the cases. TIMI thrombus grade 0 to 3 was seen in 1.2% in the DS-group vs 18% in the IS-group. Lesions were also longer on average, in the IS-group (median: 18mm versus 16mm). There were no significant differences in the initial TIMI flow or in the collateral vessels according to the Rentrop grade.
Deferred stenting (n = 80) N (%) | Immediate stenting (n = 160) N (%) | OR[CI95%]
| P
| |
| All cause death | 2 (2.5) | 4 (2.5) | 1 [0.18 – 5.58] | 1 |
| Unplanned target lesion revascularization | 7 (8.8) | 5 (3.2) | 0.34 [0.10 – 1.10] | 0.11 |
| Myocardial reinfarction | 7 (8.8) | 5 (3.2) | 0.34 [0.10 – 1.10] | 0.11 |
| Stroke | 1 (1.2) | 1 (0.62) | 0.50 [0.31 – 8.01] | 1 |
| Hemorrhage | 5 (6.3) | 7 (4.4) | 0.68 [0.21 – 2.21] | 0.54 |
| Renal failure | 4 (5.1) | 11 (6.9) | 1.38 [0.43 – 0.43] | 0.78 |
| CPK (U/L) | 1772 [724; 2976] | 1402 [552; 2569] | 0.14 | |
| Admission LVEF, % | 46.64 + 8.52 | 48.62 + 7.86 | 0.32 | |
| Length of stay (days) | 8.00 [7.00; 11.0] | 4.00 [3.00; 6.00] | 0.73 [0.66 – 0.81] | <0> |
Table 1 appendix : Intra-hospital outcomes
Deferred stenting(n = 80) N (%) | Immediate stenting (n = 160) N (%) | P
| ||
| Vessel location (by lesion) | 1 - | |||
| Left anterior descending | 24 (30) | 48 (30) | ||
| Left circumflex | 14 (18) | 28 (18) | - | |
| Right coronary artery | 42 (52) | 84 (52) | - | |
| Bifurcation | 11 (14) | 16 (10) | 0.41 | |
| Coronary status | 1 | |||
| Mono-truncal | 54 (67.5) | 108 (67.5) | - | |
| Bi-truncal | 19 (23.75) | 38 (23.75) | - | |
| Tri-truncal | 7 (8.8) | 14 (8.8) | - | |
| Calcification | 12 (15) | 9 (5.7) | 0.02 | |
| Thrombus burden | 80 (100) | 145 (91) | < 0> | |
| TIMI Thrombus grade | 0 | 0 (0) | 5 (3.1) | < 0> |
| 1 | 0 (0) | 7 (4.4) | - | |
| 2 | 0 (0) | 3 (1.9) | - | |
| 3 | 1 (1.2) | 13 (8.1) | - | |
| 4 | 21 (26) | 21 (13) | - | |
| 5 | 58 (72) | 111 (69) | - | |
| Vessel diameter (mm) | 3.00 [2.75; 3.50] | 3.00 [2.75; 3.50] | 0.09 | |
| Lesion length (mm) | 18.0 [16.0; 26.0] | 16.0 [12.0; 22.0] | < 0> | |
| Collaterality (Rentrop) | 0 | 34 (42) | 59 (37) | 0.51 |
| 1 | 25 (31) | 62 (38) | - | |
| 2 | 21 (26) | 39 (25) | - | |
| 3 | 0 (0) | 0 (0) | - | |
| Initial TIMI flow grade | 0 | 58 (72) | 113 (71) | 0.08 |
| 1 | 8 (10) | 6 (3.8) | - | |
| 2 | 11 (14) | 24 (15) | - | |
| 3 | 3 (3.8) | 17 (11) | - |
Table 2: Angiographic and lesion characteristics
The acute procedural data did not differ significantly between the two groups, as shown in Table 3 except for the number of stents. Although not significant, there was a trend towards more frequent use of thrombo-aspiration in the DS-group (37% vs 25%, p = 0.07). The use of a GPI therapy (52% versus 33%, p = 0.01) of which 18% vs 5% (p < 0> 12h was more frequent in the DS-group. There was no significant difference in the procedural use of anti-thrombin and anti-platelet therapy between the 2 groups.
Deferred stenting* (n = 80) N (%) | Immediate stenting (n = 160) N (%) | P | |
| Guidewiring | 77 (95) | 160 (100) | 0.11 |
| Thrombectomy | 29 (37) | 40 (25) | 0.07 |
| Use of balloon | 54 (68) | 91 (57) | 0.13 |
| Stent implanted (mean +SD) | 0 (0) | 1.19 + 0.47 | - |
| Anti-thrombin | 78 (98) | 148 (93) | 0.15 |
| ASA | 79 (99) | 158 (99) | 1 |
| Ticagrelor | 60 (75) | 98 (62) | 0.05 |
| Prasugrel | 9 (11) | 20 (13) | 0.11 |
| Clopidogrel | 4 (5) | 12 (7.6) | 0.57 |
| Glycoprotein inhibitors | 42 (52) | 52 (33) | 0.01 |
| Pursuit anti-thrombin therapy | 77 (96) | 31 (19) | - |
| Length of antithrombin therapy (days), median | 6.00 [4.00; 7.00] | 1.00 [1.00; 2.00] | < 0> |
| Pursuit GPI infusion for >12hours | 14 (18) | 8 (5) | < 0> |
| Fluoroscopy time (min)* | 9.45 [6.25; 17.0] | 8.47 [6.34; 12.5] | 0.33 |
| Total PDS (cGy)* | 5952 [3315; 11726] | 5480 [3629; 9322] | 0.43 |
| Total contrast used (mL)* | 150 (60.4) | 164 (55.8) | 0.58 |
*First procedure
Table 3: Initial procedural characteristics and anti-thrombotic management
Post-procedural anti-thrombotic regimen consisted of a curative antithrombin therapy with a median duration of 6 days in 96% of the patients in the DS-group. In the IS-group 19% of the patients benefited from a post-procedural curative antithrombin therapy for a median duration of 24hours. Angiographic outcomes after 2nd procedure (DS-group) and the initial procedure (IS-group) are summarized in Table 4.
Deferred stenting (n = 80) N (%) | Immediate stenting (n = 160) N (%) | P | ||
| TIMI flow grade | 0 | 0 (0) | 0 (0) | 0.01 |
| 1 | 0 (0) | 6 (3.8) | - | |
| 2 | 4 (5.1) | 24 (15) | - | |
| 3 | 75 (95) | 130 (81) | - | |
| Myocardial blush grade | 0 | 0 (0) | 6 (3.8) | < 0> |
| 1 | 6 (7.6) | 33 (21) | - | |
| 2 | 25 (32) | 53 (33) | - | |
| 3 | 48 (61) | 68 (42) | - | |
| No reflow | 7 (8.9) | 42 (26) | < 0> | |
| Distal embolization | 3 (3.8) | 28 (18) | < 0> | |
| Final stent number, mean+ SD | 0.81 + 0.72 | 1.19 + 0.47 | < 0> | |
| Patients with stent implanted | 57 (61) | 160 (100) | - | |
| Total contrast used (mL) | 261 [204 ; 316] | 152 [125 ; 189] | < 0> | |
| Total PDS used (cGy) | 10185 [5798; 17319] | 5479 [3624; 9329] | < 0> |
Table 4: Angiographic results after final procedure
Coronary flow evaluated by TIMI flow grade and myocardial perfusion estimated by myocardial blush grade (MBG) was significantly higher in the DS-group versus the IS-group. On the contrary no reflow (8.9% vs 26%; p < 0>
Intra-hospital outcomes are recapitulated in Table 1 appendix. There was no statistically significant difference in intra-hospital event rates between the two groups. Hospital stay was significantly longer in the DS-group, with a median of 8 days versus 4 days in the DS-group (p < 0>
| Deferred stenting (n = 80) | Immediate stenting (n = 160) | p | |
| LVEF within 24 months, mean (SD) | 52.8 + 8.1 | 51.9 + 8.9 | 0.43 |
| Median delay LVEF within 24 months | 13.0 [10.0 ; 18.0] | 14.0 [11.0; 19.0] | 0.29 |
| LVEF latest, mean (SD) | 53.3 + 7.9 | 52.3 + 9.1 | 0.43 |
| Median delay LVEF latest | 37 [20.0 – 55.0] | 35 [24.0 – 53.0] | 0.95 |
| Myocardial necrosis, mean % (SD) | 15.2 + 8.2 | 19.2 + 12.6 | 0.23 |
Table 2 appendix: Left ventricular ejection fraction and myocardial necrosis
Table 2 appendix shows the evolution of left ventricular ejection fraction obtained in 216 (90%) patients at a median follow-up of 13.5 months. There was no statistically significant difference between the 2 groups. The size of the necrosis measured isotopically was recorded in 89 patients (37%), and showed no significant difference but a trend towards a smaller median necrotic area with 10% in the DS-group versus 15% in the IS-group.
Deferred stenting (n = 80) N (%) | Immediate stenting (n = 160) N (%) | OR[CI95%] | p | |
| At 1 year | ||||
| Composite primary outcome (MACCE) | 16 (20) | 20 (13) | 0.57 [0.28 – 1.18] | 0.13 |
| Composite primary outcome (MACE) | 14 (18) | 19 (12) | 0.64 [0.30 – 1.34] | 0.23 |
| All cause death | 5 (6.2) | 8 (5) | 0.79 [0.25 – 2.50] | 0.76 |
| Myocardial reinfarction | 8 (10) | 7 (4.4) | 0.41 [0.14 – 1.18] | 0.09 |
| Unplanned target lesion revascularization | 10 (12) | 8 (5) | 0.37 [0.14 - 0.97] | 0.04 |
| Hospital admission for heart failure | 2 (2.5) | 3 (1.9) | 0.74 [0.12 – 4.55] | 1 |
| Stroke | 3 (3.8) | 2 (1.2) | 0.33 [0.05 – 1.98] | 0.34 |
| At 2 years | ||||
| Composite primary outcome (MACCE) | 21 (26) | 26 (16) | 0.55 [0.28 – 1.05]
| 0.07 |
| Composite primary outcome (MACE) | 19 (24) | 25 (16) | 0.60 [0.31 – 1.16] | 0.13 |
| All cause death | 10 (12) | 8 (5) | 0.52 [0.21 – 1.27] | 0.15 |
| Myocardial reinfarction | 10 (12) | 9 (5.6) | 0.42 [0.16 – 1.07] | 0.06 |
| Unplanned target lesion revascularization | 10 (12) | 10 (6.2) | 0.47 [0.19 – 1.17] | 0.1 |
| Hospital admission for heart failure | 2 (2.5) | 4 (2.5) | 1 [0.18 – 5.58] | 1 |
| Stroke | 3 (3.8) | 4 (2.5) | 0.66 [0.14 – 3.01] | 0.69 |
Table 5: Clinical outcomes at 1 year and 2 years are summarized
Clinical outcomes at 1 year and 2 years are summarized in Table 5. The composite primary endpoint of all-cause mortality, recurrent infarction and unplanned revascularization of the target lesion, hospital admission for heart failure and stroke at 2 years were not significantly different (21 [26%] vs 26 [16%], OR 0.55 [0.28 – 1.05], p = 0.07) but with a trend in favor of the IS-group. Individual components of the composite endpoint were also non-significantly different, with a trend towards a higher myocardial reinfarction rate in the DS-group (10 [12%] vs 9 [5.6%], OR 0.42 [0.16 – 1.07], p = 0.06). Results were consistent with the one-year data, with the exception of a significant difference in the occurrence of an unplanned revascularization of the culprit lesion (10 [12%] vs 8 [5%], OR 0.37 [0.14 – 0.97], p = 0.04) at 1 year in the DS-group.
At 1 year
| Deferred stenting (n = 80) N (%) | Immediate stenting (n = 160) N (%) | OR[CI95%] | P |
| Composite primary outcome (MACCE) | ||||
| Sub-group 1 (n = 21 vs 42) | 2 (9.5) | 8 (19.0) | 2.24 [0.43 – 11.62] | 0.47 |
| Sub-group 2 (n = 35 vs 70) | 6 (17.1) | 8 (11.4) | 0.62 [0.20 – 1.97] | 0.42 |
| Sub-group 3 (n = 8 vs 16) | 2 (25.0) | 2 (12.5) | 0.43 [0.05 – 3.79] | 0.58 |
| Sub-group 4 (n = 16 vs 32) | 6 (37.5) | 2 (12.5) | 0.11 [0.02 – 0.64] | 0.01 |
| Composite primary outcome (MACE) | ||||
| Sub-group 1 (n = 21 vs 42) | 1 (4.8) | 8 (19.0) | 4.7 [0.55 – 40.44] | 0.25 |
| Sub-group 2 (n = 35 vs 70) | 5 (14.3) | 7 (10.0) | 0.67 [0.20 – 2.28] | 0.52 |
| Sub-group 3 (n = 8 vs 16) | 2 (9.5) | 2 (12.5) | 0.43 [0.05 – 3.79] | 0.58 |
| Sub-group 4 (n = 16 vs 32) | 6 (17.1) | 2 (12.5) | 0.11 [0.02 – 0.64] | 0.01 |
At 2 years
| Deferred stenting (n = 80) N (%) | Immediate stenting (n = 160) N (%) | OR[CI95%] | P |
| Composite primary outcome (MACCE) | ||||
| Sub-group 1 (n = 21 vs 42) | 6 (28.6) | 11 (26.2) | 0.89 [0.26 – 2.86] | 0.84 |
| Sub-group 2 (n = 35 vs 70) | 7 20.0) | 11 (15.7) | 0.75 [0.26 – 2.13] | 0.58 |
| Sub-group 3 (n = 8 vs 16) | 2 (25.0) | 2 (12.5) | 0.43 [0.05 – 3.79] | 0.58 |
| Sub-group 4 (n = 16 vs 32) | 6 (37.5) | 2 (12.5) | 0.11 [0.02 – 0.64] | 0.01 |
| Composite primary outcome (MACE) | ||||
| Sub-group 1 (n = 21 vs 42) | 5 (23.8) | 11 (26.2) | 1.14 [0.34 – 3.84] | 0.84 |
| Sub-group 2 (n = 35 vs 70) | 6 (17.1) | 10 (14.3) | 0.81 [0.27 – 2.43] | 0.70 |
| Sub-group 3 (n = 8 vs 16) | 2 (25.0) | 2 (12.5) | 0.43 [0.05 – 3.79] | 0.58 |
| Sub-group 4 (n = 16 vs 32) | 6 (37.5) | 2 (12.5) | 0.11 [0.02 – 0.64] | 0.01 |
Table 6: Sub-groups outcome
Table 6 shows the primary outcome in the 4 sub-groups, stratified according to the administration of an optimal anti-thrombotic protocol and according to angiographic and clinical conditions retained favorable to deferred stenting.
A total of 21 patients in the DS-group received 5-7 days of anti-thrombin therapy in combination with a dual anti-platelet therapy, independently of GPIIb/IIIa administration (defined as optimal antithrombotic protocol) and had a Rentrop collaterality grade > 1 combined with an ischemia time of > 6 h (sub-group 1). Sub-group 4 consisted of 16 patients who had not received an optimal anti-thrombotic protocol, had no collaterality and an ischemia time < 6h xss=removed>
Sub-group 1 At 1 year | Deferred stenting (n = 21) N (%) | Immediate stenting (n = 42) N (%) | OR[CI95%]
| P |
| Composite primary outcome (MACCE) | 2 (9.5) | 8 (19.0) | 2.23 [0.43 – 11.62] | 0.47 |
| Composite primary outcome (MACE) | 1 (4.8) | 8 (19.0) | 4.71 [0.55 – 40.44] | 0.25 |
| All cause death | 0 (0) | 3 (7.1) | 3.81 [0.19 – 77.25] | 0.54 |
| Myocardial reinfarction | 0 (0) | 4 (9.5) | 5.03 [0.26 – 97.95] | 0.29 |
| Unplanned target lesion revascularization | 0 (0) | 3 (7.1) | 3.81 [0.19 – 77.25] | 0.54 |
| Hospital admission for heart failure | 1 (4.8) | 1 (2.4) | 0.49 [0.03 – 8.21] | 1.00 |
| Stroke | 1 (4.8) | 1 (2.4) | 0.49 [0.03 – 8.21] | 1.00 |
Sub-group 1 At 2 years | Differate stenting (n = 21) N (%) | Immediate stenting (n = 42) N (%) | OR[CI95%]
| P |
| Composite primary outcome (MACCE) | 6 (28.6) | 11 (26.2) | 0.89 [0.27 – 2.86] | 1 |
| Composite primary outcome (MACE) | 5 (23.8) | 11 (26.2) | 1.13 [0.34 – 3.83] | 1 |
| All cause death | 3 (14.3) | 5 (11.9) | 0.81 [0.17 – 3.77] | 1 |
| Myocardial reinfarction | 1 (4.8) | 5 (11.9) | 2.70 [0.29 – 24.76] | 0.65 |
| Unplanned target lesion revascularization | 0 (0) | 4 (9.5) | 5.03 [0.26 – 97.95] | 0.29 |
| Hospital admission for heart failure | 1 (4.8) | 2 (4.8) | 1 [0.08 – 11.70] | 1.00 |
| Stroke | 1 (4.8) | 2 (4.8) | 1 [0.08 – 11.70] | 1.00 |
Sub-group 4 At 1 year | Differate stenting (n = 16) N (%) | Immediate stenting (n = 32) N (%) | OR[CI95%]
| P |
| Composite primary outcome (MACCE) | 6 (37.5) | 2 (6.25) | 0.11 [0.02 – 0.64] | 0.01 |
| Composite primary outcome (MACE) | 6 (37.5) | 2 (6.25) | 0.11 [0.02 – 0.64] | 0.01 |
| All cause death | 2 (12.5) | 1 (3.12) | 0.23 [0.02 – 2.70] | 0.25 |
| Myocardial reinfarction | 4 (25) | 0 (0) | 0.04 [0.01 – 0.80] | < 0> |
| Unplanned target lesion revascularization | 5 (31.2) | 1 (3.12) | 0.07 [0.01 – 0.68] | 0.01 |
| Hospital admission for heart failure | 0 (0%) | 0 (0%) | - | - |
| Stroke | 0 (0%) | 0 (0%) | - | - |
Sub-group 4 At 2 years | Differate stenting (n = 16) N (%) | Immediate stenting (n = 32) N (%) | OR[CI95%] | P |
| Composite primary outcome (MACCE) | 6 (37.5) | 2 (6.25) | 0.11 [0.02 – 0.64] | 0.01 |
| Composite primary outcome (MACE) | 6 (37.5) | 2 (6.25) | 0.11 [0.02 – 0.64] | 0.01 |
| All cause death | 2(12.5) | 1 (3.12) | 0.23 [0.02 – 2.70] | 0.25 |
| Myocardial reinfarction | 5 (31.25) | 0 (0) | 0.03 [0.01 – 0.59] | < 0> |
| Unplanned target lesion revascularization | 5 (31.2) | 1 (3.12) | 0.07 [0.01 – 0.68] | 0.01 |
| Hospital admission for heart failure | 0 (0) | 0 (0) | - | - |
| Stroke | 0 (0) | 0 (0) | - | - |
Table 3 appendix: Composite primary outcome in sub-groups 1 and 4
The main findings of the current study comparing a deferred versus and immediate stenting strategy for the treatment of AMI suggest: (1) a rheological better acute end-of-procedure outcome with the deferred stenting strategy, (2) a numerically better LVEF with a smaller necrotic extension following the deferred stenting strategy (3) the overall absence of a clinical benefit from a deferred stenting strategy, with a trend towards an increased incidence of MACCE and MACE at 2 years and (4) a significantly unfavorable outcome of the deferred stenting strategy in the sub-group receiving an incomplete antithrombotic therapy, with a lack of collateral circulation distal to the culprit lesion combined with a short ischemia time (<6h>
The DANAMI3-DEFER study, the largest prospective randomized trial to date studying this therapeutic strategy, found no significant difference in clinical outcomes in an unselected STEMI population at 4 years follow-up.(3) A meta-analysis carried out by Qiao et al. in 2017 including almost all studies on delayed stenting strategy as well as the latter study found a trend towards a reduction in MACE in favor of the deferred stenting group, without however reaching significance.(27) In the current study, the incidence of MACE in the DS-group was largely led by revascularization of the culprit lesion and reinfarction with 70% of occurrence during the intra-hospital period between the two procedures. The incidence of reinfarction during the intra-hospital period was 8.8% in the DS-group (Table 5), which was higher than observed in the literature (reported range between 2% and 7% in randomized trials).(3,14,16) This may be explained by a low use of GPI in the DS-group (52%) among which solely 33% (n=14) benefited from a GPI infusion for at least 12h following the procedure. In the trial of Tang et al.(19), a GPI infusion was systematically administered for 72 to 96 hours, with no cases of re-occlusion reported. This was observed also in the DEFER-STEMI randomized trial(16), in which 98% of the patients in the delayed stenting group received a 12h post-procedural GPI infusion with only 2 cases experiencing a re-occlusion. Also in the current study, no cases of re-infarction were detected in between the two procedures in patients (n = 14) receiving a bolus followed by a post-procedural infusion of GPI for at least 12h. Of interest in patients (n = 28) receiving only a bolus of GPI, 4 (14%) experienced an occlusion, demonstrating the importance of a continuous infusion when the use of GPI inhibitors seemed procedurally indicated. A further explanation of the increased re-occlusion and MI rate in the DS-group could be an initially lower thrombus burden and TIMI thrombus grade associated with a numerically higher TIMI 3 flow in the IS-group (Table 2), which may have influenced also overall long-term prognosis. Lastly, the median time between procedures was 6 days in the current series, which is longer than in most previous trials and performed wittingly following observational dissolution of coronary thrombus mostly following >5 days of antithrombotic therapy. This strategy proved also previously its feasibility in a retrospective trial by Ke et al. in which nearly complete thrombus dissolution was observed after at least 7 days of curative anticoagulation.(18)
The stratification in four sub-groups according to antithrombotic protocol, presence of collaterals and ischemia time (Table 6), revealed a significant increase in the incidence of MACCE at one and two years in the sub-group receiving an antithrombotic protocol for < 5> 5 days, presenting late and with sufficient collaterals distal to the culprit lesion showed a numerical trend favoring a deferred stenting strategy at 1 year, which however faded away at 2 years follow-up. Further of interest the observed almost absence of unplanned lesion revascularization and myocardial infarction at 1 and 2 years.
Limitations: Firstly, this is a retrospective, nonrandomized, monocentric trial, and a potential selection bias of the included patients may have occurred. Even though the number of operators accustomed to manage AMI is small and potentially allowing the development of a Center related strategy to treat AMI, the final choice and criteria of a deferred stenting strategy remained operator dependent. The current potential selection bias may also been as an advantage as solely patients retained unsuitable for a direct stenting strategy were selected. In this real world clinical setting the selected AMI patient population was characterized by an important thrombus burden. In fact solely 3% (80/2621) of the AMI patients were not retained suitable for a direct stenting strategy in the period from 2014 to 2020. Secondly, even though carefully executed the matching process may have a bias. The currently used 1:2 matching process according to risk factor of thrombus-related event aimed however to improve reliability of the matched patient population and of the statistical analysis. Nevertheless thrombus burden and TIMI flow were lower in the control-group, setting a higher bar to the deferred stenting strategy to demonstrate a benefit. Thirdly, as with any retrospective trial, there is an information bias, with data that may be incomplete or missing.
In conclusion, this study suggests that deferred stent implantation in AMI patients does not appear to reduce MACCE/MACE rates compared with standard immediate PCI and may be associated with an increased rate of target lesion revascularization and reinfarction. It further suggests that in certain subgroup deferred stenting should be avoided and that it may be attempted in the presence of an important thrombus burden and in the presence of collaterals as well as of late presentation.
Clearly Auctoresonline and particularly Psychology and Mental Health Care Journal is dedicated to improving health care services for individuals and populations. The editorial boards' ability to efficiently recognize and share the global importance of health literacy with a variety of stakeholders. Auctoresonline publishing platform can be used to facilitate of optimal client-based services and should be added to health care professionals' repertoire of evidence-based health care resources.
