Impact of ventricular arrhythmias on survival in patients after myocardial infarction

Abstract

Introduction: Despite the continuous development of new methods of pharmacological and invasive treatment for patients with acute myocardial infarction (MI) the prognosis of long-term survival is still uncertain. Therefore, there is still need to look for new noninvasive predictors of death in patients after MI.

Aim: To analyze the prognostic value of ventricular arrhythmias in predicting mortality following MI in long-term follow-up.

Methods: We analyzed 390 consecutive patients (114 females and 276 males, aged 63.9 ± 11.15 years, mean EF: 43.8 ± 7.9%) with MI treated invasively.  On the 5th day after MI 24-hour digital Holter recording was performed to assess the number of premature ventricular beats (VPB) and their sustained forms such as: salvos and nonsustained ventricular tachycardia (nsVT <  30 s). The large numbers of ventricular extrasystoles: ≥ 10 VPB / hour were considered as abnormal. In echocardiography the size of heart cavities and cardiac contractile function were evaluated. Within 30.1 ± 15.1 months of follow-up 38 patients died.

Results: In the group of patients with MI the mean value of ventricular ectopy during the day was: 318.8 ± 1447.6. Large numbers of ventricular extrasystoles were observed in 75% patients, while nsVT in 6% patients. Significant differences in the incidence of death after MI were observed in patients with nsVT and ventricular salvos. In the group of patients who died in comparison to the group of patients who survived in long-term follow-up, a significantly less ventricular ectopic incidence was noted (9.83% vs 90.17%, p < 0.01). In patients who died after MI more premature ventricular beats (≥ 10 VPB / h) and a greater nsVT incidence were observed; however not significant. Moreover, in patients with MI the systolic and diastolic LV dimension, decreased values of hemoglobin, salvos and nsVT incidence are the independent risk factors of death. The strongest independent risk factor of death after MI is salvos (HR: 1.32, P < 0.01).

Conclusions: In long term follow-up the largest differences in death were observed in patients with ventricular salvos and nsVT. Furthermore, ventricular salvos are the strongest independent risk factor of death in patients with AMI.