Determinants of severity of left ventricular dysfunction in Australian men and women with coronary disease aged 65 years or less

BACKGROUND: The degree of left ventricular (LV) impairment is an important determinant of long term outcome in patients with coronary artery disease (CAD). AIM: We aimed to determine variables predictive of the severity of LV dysfunction in men and women aged 65 years or less with CAD, and to quantitate their contributions. METHODS: We documented atherogenic variables and extent of LV impairment and CAD severity at angiography in 521 consecutively studied men and women aged 65 years or less (381 males and 140 females). We assessed severity from an LV impairment score (Green Lane) and the ejection fraction. We related severity to quantitative and categorical variables which included the severity of angina (no angina, stable and unstable angina). RESULTS: The LV impairment score correlated closely (negatively) with the ejection fraction (r = -0.783, p = 0.0001). There were eight variables independently predictive of the severity of LV impairment assessed by the LV score. The variables in descending order of relative importance in predicting the LV scores were past history of myocardial infarction (MI), number of significantly diseased vessels (> 50% luminal obstruction), life-time smoking dose, log-triglycerides, total cholesterol to HDL-C ratio, hypertension, age and Body Mass Index (BMI). They were all positive relationships. Together they correctly classified the LV scores of 52.6% of the patients. Gender was not an independent contributor to the LV score when other variables were controlled. When the contributions to the variance in LV scores of past history of MI (15.4%) and number of significantly diseased vessels (2.6%) were controlled, life-time smoking dose independently explained 2.1% (p < 0.01) of the variance. The LV impairment score was 55% higher in heavy smokers than in non-smokers (p = 0.01). When we compared patients with stable and unstable angina, LV scores are higher and ejection fraction lower in the unstable angina patients consistent with them having a greater degree of LV dysfunction. CONCLUSION: We conclude that variables other than a history of MI and CAD severity contribute significantly to the variance of the degree in LV impairment in CAD patients among which the life-time smoking dose, triglycerides, TC/HDL-C, hypertension and increased BMI are all relevant to prevention, and that patients with unstable vs stable angina usually have more impaired LV function.