Ten-year mortality rates in the RITA-3 trial were similar regardless of whether patients with non-ST-segment elevation acute coronary syndrome underwent invasive treatment routinely or selectively, researchers reported July 27 in the Journal of the American College of Cardiology.
Prospective trials therefore will need to keep exploring which patients benefit from routine early invasive treatment, Dr. Robert A. Henderson at Nottingham University Hospitals in the United Kingdom, and his associates, wrote.
The RITA-3 (Third Randomised Intervention Treatment of Angina) trial randomized 1,810 patients with non-ST segment elevation acute coronary syndrome (NSTEMI ACS) to either routine or selective invasive treatment. Routine treatment consisted of coronary arteriography within 72 hours of the index episode of myocardial ischemia, with myocardial revascularization when clinically indicated. The selective strategy centered on antiangina medications. Patients only underwent coronary arteriography if they experienced recurrent ischemic pain at rest or during minimal exertion, with transient or persistent electrocardiographic ischemia (J. Am. Coll. Cardiol. 2015; 66: 511-20 [10.1016/j.jacc.2015.05.051]).
At 5 years, routine invasive treatment had a lower odds of cardiovascular death and myocardial infarction than selective invasive treatment, as well as a lower odds of all-cause mortality, the researchers previously reported (Lancet. 2005; 366: 914-20).
But at 10 years, all-cause mortality was 25% for both groups, and rates of cardiovascular death were 15% and 16% for routine versus selective invasive strategies (P = 0.65), they wrote. Age, history of previous myocardial infarction, heart failure, smoking, diabetes, heart rate, and ST-segment depression all predicted 10-year mortality in the multivariable analysis, but randomization strategy did not, they added.
When the researchers stratified patients based on Global Registry of Acute Coronary Events (GRACE) scores, death rates ranged from 14% for low-risk patients to 56% for high-risk patients, but did not vary by treatment strategy. The results highlight the need for more trials of intervention strategies for NSTEMI ACS, the researchers concluded.
The British Heart Foundation funded the RITA-3 trial and received relevant support from Aventis Pharma. One of the study co-authors reported receiving grant support from The Medicines Company, and the authors reported having no relevant financial disclosures.