Long-Term Survival after Invasive or Conservative Strategy in Elderly Patients with non-ST-Elevation Myocardial Infarction: A Prospective Cohort Study

Background: The optimal management of elderly patients with non-ST-segment elevation myocardial infarction (NSTEMI) is still discussed. We aimed to study short- and long-term survival in NSTEMI patients ≥75 years managed with an invasive or a conservative strategy. Methods: NSTEMI patients admitted to Oslo University Hospital Ulleval during 2005–2011 were included consecutively in a prospective registry. Vital status until December 31, 2013, was obtained from the Norwegian Cause of Death Registry. Patients ≥75 years were identified, and 30-day and 7-year survival were analyzed. Logistic- and Cox regression was used to estimate OR and hazard ratio (HR) for death in the invasive versus conservative group, adjusting for registered confounders. Results: There were 2,064 NSTEMI patients ≥75 years (48.2% women); 1,200 (58.1%) were treated with an invasive strategy, and were younger, more likely to be male and previously revascularized compared to 864 (41.9%) patients treated conservatively (p < 0.0001 for all). Survival at 30-day was 94.9% in the invasive and 76.6% in the conservative group. For 30-day survivors, 7-year survival was 47.4% (95% CI 42.9–51.8) and 11.6% (95% CI 8.3–15.6), respectively. After multivariate adjustment, an invasive strategy was associated with lower long-term risk (adjusted HR [aHR] 0.49 [95% CI 0.41–0.59]). Actual revascularization was associated with lower risk of long-term mortality compared to angiography only (aHRPCI 0.73 [95% CI 0.59–0.90], aHRCABG 0.43 [95% CI 0.28–0.65]). Conclusion: In this real-life cohort of NSTEMI patients ≥75 years, 30-day survival was 95%, and 7-year survival was 47% with an invasive strategy. Revascularized patients had a superior long-term prognosis. With a conservative strategy, short- and long-term survival was lower, probably due to selection bias and unmeasured confounding.