Intra-aortic balloon counterpulsation reduces mortality in large anterior myocardial infarction complicated by persistent ischaemia: a CRISP-AMI substudy

Aims: This substudy investigated IABP support in large STEMI complicated by persistent ischaemia within the original CRISP-AMI trial. Methods and results: Patients were included if the ECG at admission showed summed ST deviation (ΣST-D) ≥15 mm and the ECG post PCI showed poor ST resolution (<50%). Endpoints evaluated were all-cause mortality at six months and the composite endpoint of death, cardiogenic shock or new or worsening heart failure at six months. One hundred and forty-nine patients had ΣST-D ≥15 mm (mean ΣST-D 24±8 mm). Of these patients, 36 (24%) showed poor ST resolution (15 patients in the IABP group; 21 patients in the control group). Mean age was 55±11 years, 89% were male. Mean systolic and diastolic blood pressures were 135±31 mmHg and 83±22 mmHg, respectively. The left anterior descending coronary artery was the infarct-related artery in all cases, primary PCI was successful in 94%. At six months, zero patients in the IABP group died versus five patients in the control group (0% versus 24%; p=0.046). There was a trend towards statistical significance in the composite endpoint (one patient [7%] versus seven patients [33%]; p=0.06). Conclusions: In this substudy, use of IABP was associated with decreased six-month mortality in large STEMI complicated by persistent ischaemia after PCI.