Long-term outcome in patients with unstable angina treated by coronary balloon angioplasty

Comparison of balloon angioplasty results in 472 patients with stable angina (SA) and 158 patients with unstable angina (UA) in 5-year follow-up is reported. Clinical success rate did not differ significantly, while periprocedural complications rate was higher in UA group (22.3 vs. 11.1%, P<0.001). During follow-up UA patients demonstrated higher: restenosis rate (48.5 vs. 30.4%, P<0.001), incidence of myocardial infarction (8.8 vs. 3.0%, P=0.004), although cardiac mortality did not differ significantly (2.2 vs. 1.6%). Reintervention rate in patients with unstable angina resultant from restenosis or significant artherosclerosis progression in coronary vessels, or originating from both of them, was also higher (53.7 vs. 34.1%, P<0.001). Event-free survival was significantly lower in UA patients (43.4 vs. 61.3%, P=0.02). The uni- and multivariate analysis proved that unstable angina was an independent risk factor in restenosis, re-intervention and cardiac events rate, despite perceptible differences in the baseline characteristics. Sub-group analysis of UA patients according to Braunwald classification revealed lower success rate and higher incidence of myocardial infarction during follow-up in post-infarction angina (class C), whereas new onset, no-rest angina (class I) had higher event-free survival in comparison with rest angina (classes II and III). Conclusions: UA patients treated by balloon angioplasty had higher periprocedural complications rate, as well as restenosis and re-intervention rate. Despite higher cardiovascular events rate during 5-year follow-up in UA group, survival rate in both groups was high and cardiac mortality did not differ significantly. Unstable angina constitutes a strong independent risk factor in adverse long-term outcome.