Results of primary percutaneous coronary intervention in a consecutive group of patients with acute ST elevation myocardial infarction at a tertiary Australian centre

BACKGROUND

Multicentre randomized controlled trials (RCT) of primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI) have consistently shown lower mortality compared with fibrinolysis, if carried out in a timely manner. Although primary PCI is now standard of care in many centres, it remains unknown whether results from RCT of selected patients are generalizable to a 'real-world' Australian setting. The primary goal of this study was to evaluate whether a strategy of routine invasive management for patients with STEMI can achieve 30-day and 12-month mortality rates comparable with multicentre RCT. Secondary goals were to determine 30-day mortality rates in prespecified high-risk subgroups, and symptom-onset- and door-to-balloon-inflation times.

METHODS

A retrospective observational study of 189 consecutive patients treated with primary PCI for STEMI in a single Australian centre performing PCI for acute STEMI.

RESULTS

All-cause mortality was 6.9% at 30 days, and 10.4% at 12 months. Mortality in patients presenting without cardiogenic shock was low (2.4% at 30 days; 5.0% at 12 months), whereas 12-month mortality in patients with shock was higher, particularly in the elderly (29.4% for patients <75 years; 85.7% for patients > or =75 years, P = 0.01). Symptom-onset-to-balloon-inflation time was < or =4 h in 56% of patients (median 231 min); however, a door-to-balloon time of <90 min was achieved in only 20% (median 133 min).

CONCLUSION

Mortality and symptom-onset-to-balloon-inflation times reported in RCT of primary PCI for STEMI are generalizable to 'real-world' Australian practice; however, further efforts to reduce door-to-balloon times are required.

Prevalence of coronary occlusion and outcome of an immediate invasive strategy in suspected acute myocardial infarction with and without ST-segment elevation

The prevalence of flow-limiting coronary lesions at the time of presentation in patients with non-ST-segment elevation myocardial infarction (NSTEMI) is unknown. Because rational reperfusion strategies depend on early, accurate identification of coronary flow limitation, we performed coronary angiography at the time of presentation of patients with suspected NSTEMI. We also evaluated outcomes of an immediate interventional strategy. A comparison is made with suspected ST-segment elevation myocardial infarction (STEMI). Unselected consecutive patients with suspected STEMI or NSTEMI were enrolled in a prospective observational cohort study. Suspected STEMI was defined according to standard criteria. Suspected NSTEMI was identified by clinical evaluation of symptoms, electrocardiographic changes, persistence of ischemic pain for >20 minutes despite treatment, and/or hemodynamic instability. Biochemical evidence of myocardial necrosis on presentation was not mandatory. An immediate, around-the-clock invasive strategy was applied. Significant coronary lesions were found in 94% of 279 patients with suspected STEMI and in 90% of 125 patients with suspected NSTEMI, and coronary occlusion or flow limitation was present in 75% and 63% of patients, respectively. Immediate percutaneous coronary intervention was performed in 74% and 60%, respectively, and an additional 13% and 18%, respectively, had coronary artery bypass surgery during the index admission. In-hospital mortalities in the patients with suspected STEMI and NSTEMI were 4.7% and 5.6%, respectively. An additional 1.9% and 2.5% died at 6 months. The prevalence of coronary flow limitation in clinically suspected NSTEMI is almost as high as in suspected STEMI. Short- and long-term outcomes of an immediate invasive strategy are similar for the 2 conditions.