Invasive strategy in non-ST elevation acute coronary syndromes: risks and benefits in an elderly population

Age is an important prognostic factor in acute coronary syndromes (ACS). An invasive strategy has been shown to benefit many non-ST elevation ACS populations; however, there is some controversy regarding patients who are more susceptible to procedure-related complications, such as the elderly, an under-represented population in the studies on this subject.

We aimed to compare the in-hospital and long-term prognosis of elderly patients with non-ST elevation ACS treated with either invasive procedures or a conservative strategy, and to characterize the patients selected for an early invasive approach.

This observational, longitudinal, prospective and continuous study included 307 patients aged over 75 years consecutively admitted for non-ST elevation ACS. They were divided into two groups, according to the approach adopted: Group A (n=91)--patients treated with an early invasive strategy; and Group B (n=216)--patients treated conservatively. The median clinical follow-up was 18 months.

The subjects who were treated invasively were younger (79.8 +/- 3.2 vs. 81.4 +/- 3.9 years, p < 0.001) and more often male (63.7 vs. 50.9%, p = 0.04), had a higher incidence of previous coronary artery disease, were more often treated with clopidogrel, and had a longer hospital stay (5.8 +/- 3.1 vs. 4.9 +/- 2.6 days, p = 0.01). Patients managed conservatively presented higher Killip class, and were more often treated with diuretics during hospitalization. The group treated by an invasive approach presented a higher incidence of in-hospital complications (13.6 vs. 4.9%, p = 0.009), but there were no significant differences in mortality rates. Multivariate analysis showed that an invasive strategy was an independent predictor of in-hospital morbidity (OR = 3.55). In follow-up, rates of MACE (56.3 vs. 33.3%, p = 0.002) and death (32.5 vs. 13.8%, p = 0.007) were higher in the group that received conservative treatment, and an invasive strategy was a protective factor against MACE; the strongest predictor of mortality was left ventricular ejection fraction <50%.

Although an invasive strategy was associated with increased in-hospital complications, it was shown to confer a better long-term prognosis. These data show that age should not be the only criterion in selecting patients for an invasive strategy and favor early adoption of this approach in the elderly.