Characteristics and outcome of patients with ST-elevation infarction in relation to whether they received thrombolysis or underwent acute coronary angiography: are we selecting the right patients for coronary angiography?

BACKGROUND: During the last decade, there has been an on-going debate with regard to whether percutaneous coronary intervention (PCI) or thrombolysis should be preferred in patients with ST-elevation acute myocardial infarction (AMI). Some studies clearly advocate PCI, while others do not.

HYPOTHESIS: The study aimed to describe the characteristics and to evaluate outcome of patients with suspected ST-elevation or left bundle-branch block infarction in relation to whether they received thrombolysis or had an acute coronary angiography aiming at angioplasty.

METHODS: The study included all patients admitted to Sahlgrenska University Hospital in Göteborg, Sweden, with suspected acute myocardial infarction who, during 1995-1999, had ST-elevation or left bundle-branch block on admission electrocardiogram (ECG) requiring either thrombolysis or acute coronary angiography. A retrospective evaluation with a follow-up of 1 year after the intervention was made.

RESULTS: In all, 413 patients had thrombolytic treatment and 400 had acute coronary angiography. The patients who received thrombolysis were older (mean age 70.3 vs. 64.1 years). Mortality during 1 year of follow-up was 20.9% in the thrombolysis group and 16.6% in the angiography group (p = 0.12). Among patients in whom acute coronary angiography was performed, only 85% underwent acute percutaneous coronary intervention (PCI). There was a mortality of 12.1 vs. 41.7% among those who did not undergo acute PCI. Development of reinfarction, stroke, and requirement of rehospitalization was similar regardless of type of initial intervention. The thrombolysis group more frequently required new coronary angiography (36.9 vs. 20.6%; p<0.0001) and new PCI (17.8 vs. 11.9%; p = 0.01). Despite this, after 1 year symptoms of angina pectoris were observed in 27% of patients in the thrombolysis group and in only 14% of those in the angiography group (p = 0.0002).

CONCLUSION: In a Swedish university hospital with a high volume of coronary angioplasty procedures, we found no significant difference in mortality between patients who had thrombolysis and those who underwent acute coronary angiography. However, requirement of revascularization and symptoms of angina pectoris 1 year later was considerably less frequent in those who had undergone acute coronary angiography. However, distribution of baseline characteristics was skewed and efforts should be focused on the selection of patients for the different reperfusion strategies.