Routine or Selective Invasive Strategy for Acute Coronary Syndrome

Summary

A Cochrane review [Abstract] 1 included 8 studies with a total of 8 915 subjects. The review compared routine invasive (routine angiography ±revascularization in all patients) and conservative or "selective invasive" (angiography ±revascularization only in eligible patients with evidence of cardiac ischemia e.g. recurrent ischemia, dynamic ECG changes or a positive stress test) strategies in participants with acute UA/NSTEMI. In the all-study analysis (regardless of glycoprotein IIb/IIIa receptor antagonist use), no risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; 8 studies, n=8 915) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; 7 studies, n=7 715) with invasive strategies compared to conservative (selective invasive) strategies were observed at 6 to 12 months follow-up. There was a risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; 8 studies, n=8 915), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; 5 studies, n=8 287) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; 6 studies, n=6 921) with routine invasive strategies compared to conservative (selective invasive) strategies also at 6 to 12 months follow-up. There was increased risks for complications of angiography or revascularization (RR for bleeding 1.73, 95% CI 1.30 to 2.31; 6 studies, n=7 584 and RR for procedure-related MI 1.87, 95% CI 1.47 to 2.37; 5 studies, n=6 380) with routine invasive strategies compared to conservative (selective invasive) strategies. Mortality during initial hospitalization showed an increase with routine invasive strategy (RR 1.54, 95% CI 1.02 to 2.34; 6 studies, n=8 094) compared with conservative (selective invasive) strategy. The authors state that available data supports the conclusion that a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

A systematic review 2 including 10 studies with a total of 10648 subjects was abstracted in DARE. The review compared a routine invasive strategy, in which all acute coronary syndrome (ACS) patients receive coronary angiography and revascularisation if appropriate, and a selective invasive strategy, in which only patients with refractory or inducible ischemia receive coronary angiography. No significant difference was found between the routine and selective invasive strategies for risk of mortality (RR 0.95, 95% CI 0.80 to 1.14), nonfatal myocardial infarction (RR 0.86, 95% CI 0.68 to 1.08), or a composite measure of death or nonfatal MI (RR 0.90, 95% CI 0.74 to 1.08) at the maximum reported follow-up (ranging from 6 to 60 months). 15.9% of patients in routine invasive strategy died or had nonfatal myocardial infarction, compared with 17.5% of those assigned to selective invasive strategy. Evidence of statistical heterogeneity was found for nonfatal MI and the composite of death or nonfatal MI.

With the removal of one large trial (ICTUS) 3, estimates for composite death/ MI (RR 0.84, 95% CI 0.74 to 0.97) and nonfatal MI alone (RR 0.77, 95% CI 0.68 to 0.88) significantly favoured the routine invasive strategy; the results for mortality did not significantly change. Exclusion of other trial individually had no effect on the study outcomes. The ICTUS trial was large (n=1200), performed provocative tests, and used stents and contemporary medical management (glycoprotein IIb/IIIa inhibitors, statins and clopidogrel). In the ICTUS study, after 3 years, the cumulative rate for the combined endpoint (death, recurrent myocardial infarction, or rehospitalisation for anginal symptoms) was 30.0% in the early invasive group compared with 26.0% in the selective invasive group (HR 1.21, 95% CI 0.97 to1.50). Myocardial infarction was more frequent in the early invasive strategy group (HR 1.61, 95% CI 1.19 to 2.18). Rates of death or spontaneous myocardial infarction were not different (HR 1.19, 95% CI 0.86 to1.67). No difference in all-cause mortality or cardiovascular mortality was seen within 4 years.