Early Revascularization for Cardiogenic Shock in the Elderly — Has the Moment of Doubt Passed?

The observational study by Amin et al1 in this issue of the Journal is another important addition to the evidence base on the benefit of early revascularization in elderly patients with acute myocardial infarction (MI) complicated by cardiogenic shock (CS). The authors studied 310 consecutive patients admitted with MI and CS at two centers. Survival was compared among treatment groups and further stratified by age. Early revascularization was associated with a significant survival benefit in younger patients as well as in the 80 patients aged ≥ 75 years, even after adjusting for confounders. The elderly patient group had a higher proportion of women and a lower proportion of patients with ST-elevation MI. Stent utilization was lower in elderly patients — 16.3% versus 33.9%. The results of registry studies, including the present report, are complementary to randomized trial data and on the whole have strengthened the case for early revascularization in patients with MI and CS, including the elderly. The SHOCK trial randomized 302 patients to early revascularization or initial medical stabilization.2 The median time from MI to CS onset was 5 hours, and the median time from MI to randomization was 11 hours in the early revascularization group. Early revascularization was associated with a trend toward decreased mortality at 30 days and a statistically significant absolute mortality reduction of 13% at 6 months, sustained at 1 and 6 years.3,4 There were 56 patients aged ≥ 75 years: 24 in the early revascularization cohort and 32 in the medical therapy group. At 6 months and 1 year, an age/treatment interaction was noted, with no significant difference in mortality between treatment groups in the subset of patients aged ≥ 75 years. However, at 6 years, no age/treatment interaction was noted, suggesting that elderly patients also benefit from early revascularization. The apparent lack of benefit of revascularization among elderly patients at the 6-month and 1-year analyses may be attributed to the small number of patients and chance differences between treatment groups. Indeed, among patients aged ≥ 75 years, those randomized to medical therapy had a higher ejection fraction and better hemodynamic response to intra-aortic balloon pump (IABP) therapy, indicators of lower mortality. 5 The low mortality rate in medically treated elderly patients (unexpectedly similar to younger patients) potentially diluted the mortality reduction achieved by early revascularization. From the University of Miami School of Medicine, Miami, Florida. The author reports no conflicts of interest regarding the content herein. Address for correspondence: Sameer Mehta, MD, University of Miami School of Medicine, Miami, Florida. E-mail: mehtas@bellsouth.net