Introduction: The aim of this study was to create a scoring system for the ICD therapy risk assesment in primary prevention in patients with coronary artery disease (CAD) and reduced left ventricular (LV) ejection fraction (EF).
Methods: Fifthy two patients (50 men, mean age 60,4 + 12,6 years) with LV EF < 40% due to prior myocardial infarction were included in our study. ICD implantation was performed in all cases for primary prevention of sudden cardiac death. Data from standard diagnostic procedures, performed before ICD implantation (coronary angiogram, echocardiogram, percent of scar, calculated using Selvester QRS score) were used for scoring system creation. Patients were divided in two groups: group 1 - 27 patients with no appropriate ICD therapy during follow-up, group 2 - 25 patients with appropriate ICD therapy. Only patients with more than 6 months follow-up were included in our study. Mean follow up was 17,3 + 11,7 months.
Results: During statistical analysis five sign were found to have OR more than 2,0. They were: LAD proximal stenosis > 75%, peripheral arterial disease, LV dilatation more, than 202 ml without wall thickening more than 11 mm, presence of right bundle brunch block, percent of scar, calculated using Selvester QRS score. Incidence of this signs is demonstrated in table 1. Using method of classification trees scoring system was created – see table 2. Statistical analysis showed higher risk of appropriate ICD therapy between patients, who had more, than 4 points of our scoring system and those, who had less or equal, than 4 points (OR 10,67, p < 0,01).
Conclusions: Our scoring system can be used for appropriate therapy risk stratification in patients with CAD and ICD implanted for primary prevention of sudden cardiac death.