Background: Percutaneous coronary catheter intervention (PCI) reduces mortality in ST-elevation myocardial infarction (STEMI) more than fibrinolysis. However, it remains uncertain whether PCI reduces the incidence of early post-infarction arrhythmias.
Material and methods: We compared the incidence of arrhythmias in two groups of consecutive STEMI-patients who underwent continuous ECG monitoring. One group was treated with PCI in 2006-07, while a historic control group received thrombolysis in 1996-98.
Results: 93 (38%) PCI patients and 97 (53%) of the thrombolysed patients (p = 0.001) had arrhythmias. 27% of the patients in the PCI group were treated for arrhythmias vs. 34% of the thrombolysed (n.s.). Significantly fewer PCI-treated patients had atrial fibrillation (5% vs. 16%), AV-block II/III (0% vs. 6%) and asystole (0% vs. 5%), but an increased frequency of ventricular tachycardia was recorded (10% vs. 5%). 41% of all arrhythmic and 63% of treated events occurred in the first hour after PCI; corresponding results for thrombolysis were 23% and 28% (p = 0.000). Mortality was greater in the thrombolysed group (11% vs. 2%, p = 0.006), but patients were older, had more risk factors and larger emit ions of cardiac enzymes. After adjustment for the confounding effects of age, gender, score for ST-elevation and infarct localization, there was still a reduction in total arrhythmias in the PCI-treated group (odds ratio 0.37, 95% confidence interval 0.19-0.73, p = 0.004).
Interpretations: PCI-treatment seems to reduce early post-STEMI arrhythmias, but a non-randomized design and the use of historical controls, reduce the strength of this conclusion.