Invasive Treatment Strategies Improve Outcomes in Patients Over 80 Years Old with Non-ST Segment Elevation Acute Coronary Syndromes
EBM Focus - Volume 11, Issue 4
- Non-ST-elevation acute coronary syndromes are common in patients ≥ 80 years old, but the appropriateness of invasive treatment strategies and early revascularization in this population is unclear.
- Compared to a conservative treatment strategy including optimum medical treatment, an invasive treatment strategy with early coronary angiography and assessment for revascularization reduced the risk of myocardial infarction and the need for urgent revascularization in clinically stable patients ≥ 80 years old presenting with non-ST-elevation myocardial infarction (NSTEMI) or unstable angina.
- The magnitude of benefit of the invasive treatment strategy decreased with age and it is unclear if this approach is appropriate for patients over 90 years old.
Immediate or early invasive treatment strategies are recommended by the American College of Cardiology Foundation and the American Heart Association for patients with non-ST-elevation acute coronary syndromes without serious comorbidities or other contraindications (Circulation 2014 Dec 23;130(25):e344). These strategies involve assessment by coronary angiography within 24 hours of admission and revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) if appropriate. Patients ≥ 80 years old are underrepresented in trials evaluating invasive treatment strategies and early revascularization, leading to uncertainty about the appropriateness of these strategies in this age group. Many physicians have been concerned whether the benefits from aggressive therapy might be offset by a higher risk of complications in this age group (Circulation 2007 May 15;115(19):2549). To further investigate the benefit and harms of early invasive treatment in older patients, 457 clinically stable patients ≥ 80 years old (mean age 85 years) admitted to the hospital with non-ST-elevation myocardial infarction (NSTEMI) or unstable angina were randomized to invasive vs. conservative treatment strategies. Conservative treatment strategy included optimum medical treatment with angiography only performed for reinfarction, refractory angina, malignant ventricular arrhythmias, or worsening heart failure. Patients were excluded for having a life expectancy< 12 months due to a serious comorbidity. Other exclusion criteria were consistent with similar trials in younger patients, including clinical factors requiring immediate intervention (such as instability due to ongoing chest pain or ischemia), and bleeding problems.
In the invasive strategy group, 47% of patients had PCI and 3% had CABG. The primary outcome was defined as the first occurring event of myocardial infarction, the need for urgent revascularization, stroke, or death. Comparing invasive vs. conservative treatment strategies over a median follow-up of 1.5 years, the primary outcome occurred in 41% vs. 61% (p = 0.0001, NNT 5). When evaluating individual components of the primary outcome, myocardial infarction occurred in 17% with the invasive strategy and 30% with the conservative strategy (p = 0.0003, NNT 8). The need for urgent revascularization was also significantly reduced in patients receiving the invasive treatment strategy (2% vs. 11%, p = 0.0001, NNT 12). However, there were no significant differences in the incidence of stroke or in all-cause mortality comparing the treatment strategies. Major bleeding was reported in 2% of patients in each group.
This is the first randomized trial to address the efficacy of an invasive treatment strategy specifically in adults over 80 years old. The benefit of the invasive strategy observed in this trial is consistent with a previous large retrospective cohort study evaluating early invasive strategies in patients ≥ 80 years old with NSTEMI or unstable angina (Am J Med 2013 Dec;126(12):1076). It is noteworthy that about one quarter of the patients screened for enrollment were excluded due to a life expectancy< 12 months. While there was a clear benefit to the early invasive strategy overall in this population, the magnitude of benefit decreased with increasing age. An analysis of patients > 90 years old found the invasive strategy appeared to increase risk for the primary outcome, but with only 34 patients in this analysis, the result was not statistically significant. A larger trial is needed to better assess the relative risks and benefits of invasive treatment in this age group.