Progression of Coronary Artery Disease During Long-Term Follow-Up of the Swiss Interventional Study on Silent Ischemia Type II (SWISSI II)

Background: This study evaluates cardiovascular risk factors associated with progression of coronary artery disease (CAD) in patients with silent ischemia following myocardial infarction. Hypothesis: Coronary artery disease only progresses slowly with comprehensive risk factor intervention. Methods: A total of 104 of 201 patients (51.7%) of the Swiss Interventional Study on Silent Ischemia Type II (SWISSI II) with baseline and follow-up coronary angiography were included. All patients received comprehensive cardiovascular risk factor intervention according to study protocol. Logistic regression was used to evaluate associations between baseline cardiovascular risk factors and CAD progression. Results: The mean duration of follow-up was 10.3 +/- 2.4 years. At baseline, 77.9% of patients were smokers, 45.2% had hypertension, 73.1% had dyslipidemia, 7.7% had diabetes, and 48.1% had a family history of CAD. At last follow-up, only 27 patients of the initial 81 smokers still smoked, only 2.1% of the patients had uncontrolled hypertension, 10.6% of the patients had uncontrolled dyslipidemia, and 2.1% of the patients had uncontrolled diabetes. Coronary artery disease progression was found in up to 81 (77.9%) patients. Baseline diabetes and younger age were associated with increased odds of CAD progression. The time interval between baseline and follow-up angiography was also associated with CAD progression. Conclusion: Coronary artery disease progression was highly prevalent in these patients despite comprehensive risk factor intervention. Further research is needed to optimize treatment of known risk factors and to identify other unknown and potentially modifiable risk factors.