Outcomes of Patients with Killip Class III Acute Myocardial Infarction After Primary Percutaneous Coronary Intervention

Objectives: Little is known about the outcomes of patients with Killip class III acute ST-segment elevation myocardial infarction in the reperfusion era. This study investigated the short- and long-term outcomes of these patients who underwent primary percutaneous coronary intervention.

Methods: Between January 2002 and November 2009, a total of 1,278 consecutive patients with acute ST-segment elevation myocardial infarction underwent primary percutaneous coronary intervention. Of these patients, 230 (17.0%) with Killip III, 216 (16.9%) with Killip II, and 832 (65.1%) with Killip I upon presentation were prospectively recruited.

Results: Angiographic study showed significantly lower final thrombolysis in myocardial infarction 3 flow in patients with Killip III compared with those with Killip II and I (83.5% vs. 94.9% vs. 95.7%, p<.0001). The incidence of multiple vessel disease was also notably higher in Killip III than in Killip II and I (65.7% vs. 13.9% vs. 53.8%, p<.001). Besides, the incidence of advanced congestive heart failure (defined as greater than or equal to New York Heart Association functional class 3) during hospitalization was remarkably higher in Killip III compared to Killip II and I (71.3% vs. 13.9% vs. 6.6%, p<.001). Furthermore, the 30-day mortality and 1-yr cumulative mortality were notably higher in Killip III than in Killip II and I (20.0% vs. 4.2% vs. 1.7%, p<.001 and 31.7% vs. 7.9% vs. 4%, p<.001, respectively). Multivariate analysis showed that Killip III was independently predictive of 30-day and 1-yr mortality (all p < .04).

Conclusion: Killip III remains strongly and independently predictive of 30-day and 1-yr mortality in ST-segment elevation myocardial infarction patients even undergoing primary percutaneous coronary intervention.