[Survival in patients with sick sinus syndrome and artificial pacemaker. Determining clinical factors]

The hypothesis that ventricular pacing is the most important factor in the survival of patients with Sick Sinus Syndrome remains controversial. The aim of this report was to determine independent clinical variables to predict survival in paced SSS patients.

Retrospective, nonrandomized study of 153 patients with a mean age of 69 +/- 11 years, who received an initial pacemaker for Sick Sinus Syndrome between 1980 and 1994: 65 physiologic pacing (32 dual chamber, 33 atrial) and 88 ventricular pacing mode. After a maximum follow up of 177 months (median 57 months) the end point was total mortality.

Total mortality was 21%. Using univariate analysis, single chamber ventricular pacing, age > or = 70 years and NYHA > or = 2, was associated with a higher risk for total mortality (4 times increased risk for ventricular pacing compared to other pacing modalities). Independent predictors using multivariate analysis were: 1) NYHA > or = 2 (p < 0.05). 2) Coronary artery disease (p < 0.01). 3) Chronic obstructive pulmonary disease (p < 0.05) and 4) Gender (p < 0.05).

Mortality in patients with the Sick Sinus Syndrome is strongly predicted by preimplant baseline clinical variables. Our data indicate that the role of ventricular pacing mode remains inconclusive. A large, randomized study is necessary to confirm these results.