STEMI Patients with Multi-vessel Disease — Culprit Vessel PCI Vs. Multi-vessel PCI

Abstract & Commentary

By Andrew J. Boyle, MBBS, PhD, Assistant Professor of Medicine, Interventional Cardiology, University of California, San Francisco. Dr. Boyle reports no financial relationships relevant to this field of study.

Source: Hannan EL, et al. Culprit vessel percutaneous coronary intervention versus multivessel and staged percutaneous coronary intervention for ST-segment elevation myocardial infarction patients with multivessel disease. J Am Coll Cardiol Intv 2010;3:22-31.

Patients presenting with ST-segment elevation myocardial infarction (STEMI) often have co-existing lesions in the non-infarct arteries (i.e., they have multi-vessel disease). These patients present a management dilemma. Should all lesions be addressed with percutaneous coronary intervention (PCI) at the time of presentation, or should only the culprit lesion be treated? If only the culprit lesion is treated, should the other lesions be medically managed or treated with staged multi-vessel PCI? Current ACC/AHA guidelines recommend treatment of the culprit lesion only, at the time of presentation with STEMI in patients who are hemodynamically stable, but multi-vessel PCI is reasonable if there is hemodynamic compromise. However, techniques have evolved over time, and some small, recent studies suggest that PCI performed not just on the culprit vessel, but on all significant lesions, may be a safe and feasible strategy. Hannan et al examined the New York PCI registry to determine the mortality of multi-vessel PCI at the time of presentation vs. culprit vessel-only PCI in STEMI patients with multi-vessel disease. Furthermore, in patients who had culprit vessel-only PCI, they examined the effects on mortality of staged multi-vessel PCI within 60 days vs. ongoing medical management.

Results: After excluding patients with missing ejection fractions (EF), left main disease, prior open-heart surgery, shock, and thrombolysis before PCI, the authors identified 4,024 patients who presented with STEMI and co-existent multi-vessel disease and underwent primary PCI between 2003 and 2006. Of these, the vast majority (87.5%, n = 3,521) underwent PCI of the culprit vessel only, and the remaining 503 (12.5%) underwent multi-vessel PCI at the time of the index procedure. Patients who had multi-vessel PCI were younger (p = 0.001), more likely to have low or high EF (p = 0.01), less likely to have chronic occlusion (p < 0.0001), less likely to have TIMI flow grade less than or equal to two in the culprit vessel before PCI (p = 0.0004), and more likely to have had bare-metal stents (BMS, p < 0.001). To compare the groups more equally, the authors performed propensity matching using clinical and anatomical factors, and identified 503 matched pairs. Overall, there was a trend toward lower mortality in the culprit-only PCI group, but this failed to reach statistical significance. When patients with hemodynamic instability, EF < 20%, and malignant ventricular arrhythmias were excluded, in-hospital mortality was significantly lower in the culprit-vessel PCI group (0.9% vs. 2.4%, p = 0.04). This trend continued at 12, 24, and 42 months.

The authors then identified patients who had received culprit vessel-only PCI at the time of the index procedure, but had received staged PCI of the other lesions, either in-hospital (n = 259) or within 60 days (n = 538). To determine the effects of staged PCI on mortality outcomes, the authors propensity-matched these patients undergoing staged multi-vessel PCI against those undergoing culprit-only PCI without further revascularization. Staged PCI during the index hospitalization had no significant effect on mortality, although those with staged PCI had a trend toward lower rates at all time-points. The authors then compared the mortality of patients who had staged multi-vessel PCI within 60 days of the index admission and those who had culprit-vessel PCI only but remained alive at 60 days. Staged multi-vessel PCI resulted in lower 12-month mortality (1.3% vs. 2.2%; p = 0.04), and this trend continued out to 42 months. The authors conclude that their findings support the ACC/AHA recommendation that culprit vessel-only PCI should be used for STEMI patients at the time of index procedure in patients who are not hemodynamically compromised. However, staged PCI within 60 days after the index admission is associated with risk-adjusted mortality rates that are comparable with the rate for culprit-vessel PCI alone.

Commentary

The findings of this study support current practice guidelines and steer clinicians away from performing multi-vessel PCI during the index procedure in hemodynamically stable patients with STEMI. Several limitations to this study must be acknowledged in interpreting the slight improvements in mortality. Firstly, this is a retrospective, observational study, not a prospective, randomized trial. Hannan et al used complex statistical models to try to account for unmeasured confounders, but the ability to draw firm conclusions from their study is limited. Secondly, there are several omissions from the dataset that could influence the primary outcome, such as the use on glycoprotein IIb/IIIa inhibitors, clopidogrel dose, timing and duration, discharge medications such as beta-blocker usage, and how many patients underwent coronary artery bypass graft surgery. Thirdly, the death statistics are taken from a state database and, thus, patients who died out of state may not have been included. Despite these limitations, several important issues are addressed here. In stable patients, there is clearly no benefit in performing multi-vessel PCI at the time of the index procedure. We use many intangible and immeasurable factors in decision making about revascularization choices. Hannan et al show us that operator discretion-based decisions to perform multi-vessel PCI at the time of primary PCI for STEMI do not decrease mortality, and may even increase it; staged PCI seems to be a better option. This study does not tell us whether staged PCI was performed based on ischemia or symptoms, or simply to achieve complete revascularization, nor are we told about other outcomes, such as quality of life, subsequent revascularization, etc. However, staged PCI appears safe, and may lead to slight improvement.