ATLANTA — A routine invasive strategy in patients with non–ST-segment elevation acute coronary syndrome results in significantly fewer cardiovascular deaths and nonfatal MIs over the subsequent 5 years than does a selective, symptom-driven revascularization approach, according to a meta-analysis of all pertinent clinical trials.
“The key result is that 5 years after the randomization there is a net absolute difference of 3.2% and a 19% relative risk reduction in cardiovascular death or MI in the routine invasive group. I don't know of any pharmacologic therapy that has that 5 years from randomization,” Dr. Keith A.A. Fox observed in presenting the meta-analysis at the annual meeting of the American College of Cardiology.
The routine invasive strategy, consisting of early angiography with an eye toward revascularization, showed significant benefit in patients with non–ST-elevation acute coronary syndrome (NSTE-ACS) deemed at low baseline risk of cardiovascular events as well as in those at higher risk. This finding constitutes a compelling argument for a change in the existing ACC/American Heart Association guidelines, which recommend a routine invasive strategy in NSTE-ACS patients with high-risk indicators, but state that in moderate- or low-risk patients the routine invasive or selective invasive approach is appropriate, said Dr. Fox, professor of cardiology at the University of Edinburgh, Scotland.
The meta-analysis is called the FIR Trial Collaboration; FIR is an acronym for the three randomized clinical trials that feature 5-year follow-up: FRISC-II (Lancet 2006;368:998-1004), ICTUS (N. Engl. J. Med. 2005;353:1095-104), and RITA 3 (Lancet 2005;366:914-20). The meta-analysis was conducted because the individual trials had inconsistent long-term findings. By combining individual patient data from the 5,467 NSTEMI patients who participated in the three trials, conclusive results emerged.
Indeed, the 5-year cumulative rate of cardiovascular death or MI was 14.7% with a routine invasive strategy compared with 17.9% with a selective invasive approach in which angiography was done only in patients with refractory angina or rest ischemia despite optimal medical therapy. The nonfatal MI rate was 10.0% with a routine invasive strategy, compared with 12.9% with a selective invasive approach, a statistically significant 23% relative risk reduction.
The absolute benefit of a routine invasive strategy was greatest in the 13% of patients who fell into the highest-risk group at baseline, but the strategy also showed significant advantages in the moderate- and low-risk groups (see chart). Furthermore, the difference in outcomes between the two strategies increased steadily over time within all three risk subgroups.
A by-product of the FIR meta-analysis was the development of a new risk-stratification scoring system that is considerably simpler than the TIMI and GRACE risk-assessment tools recommended in current guidelines. It can be easily figured at the bedside without a personal digital assistant. The risk score assigns one or more points based on age, body mass index, diabetes, ECG evidence of ischemia, hypertension, and prior MI.
Discussant Donald E. Cutlip called the FIR Trial Collaboration “an extremely valuable analysis,” but advised Dr. Fox and coworkers against putting heavy emphasis on the new risk-stratification method because it undercuts the study's key message, which is that routine invasive management of NSTE-ACS is beneficial for patients across the full spectrum of risk.
“That's what's different about this study from current thinking. We already assume there's benefit in the high-risk population; to see it in low-risk patients is an important observation,” said Dr. Cutlip, an interventional cardiologist at Beth Israel Deaconess Medical Center, Boston.
The meta-analysis was funded by the British Heart Association and the host academic institutions for the three trials. Dr. Fox disclosed serving as a consultant to Sanofi-Aventis and Bristol-Myers Squibb.
Source Elsevier Global Medical News
'I don't know of any pharmacologic therapy that has [such a result] 5 years from randomization.'
Source DR. FOX
