Preoperative prediction of significant coronary artery disease in patients with valvular heart disease

A prediction score for significant coronary artery disease in Chinese patients ≥50 years old referred for rheumatic valvular heart disease surgery

OBJECTIVES

Our goal was to establish a prediction score and protocol for the preoperative prediction of significant coronary artery disease (CAD) in patients with rheumatic valvular heart disease.

METHODS

Using multivariate logistic regression analysis, we validated the model based on 490 patients without a history of myocardial infarction and who underwent preoperative screening coronary angiography. Significant CAD was defined as ≥50% narrowing of the diameter of the lumen of the left main coronary artery or ≥70% narrowing of the diameter of the lumen of the left anterior descending coronary artery, left circumflex artery or right coronary artery.

RESULTS

Significant CAD was present in 9.8% of patients. Age, smoking, diabetes mellitus, diastolic blood pressure, low-density lipoprotein cholesterol and ischaemia evident on an electrocardiogram were independently associated with significant CAD and were entered into the multivariate model. According to the logistic regression predictive risk score, preoperative coronary angiography is recommended in (i) postmenopausal women between 50 and 59 years of age with ≥9.1% logistic regression predictive risk score; (ii) postmenopausal women who are ≥60 years old with a logistic regression predictive risk score ≥6.6% and (iii) men ≥50 years old whose logistic regression predictive risk score was ≥2.8%. Based on this predictive model, 246 (50.2%) preoperative coronary angiograms could be safely avoided. The negative predictive value of the model was 98.8% (246 of 249).

CONCLUSIONS

This model was accurate for the preoperative prediction of significant CAD in patients with rheumatic valvular heart disease. This model must be validated in larger cohorts and various populations.

[Preoperative coronarography in heart valve disease patients. A probability analysis of coronary lesion]

INTRODUCTION AND OBJECTIVES

The indication of preoperative coronary angiography is routinely performed for patients who are going to valve replacement surgery. The need of coronary angiography is based on age, gender and previous angina, but it is not usually based on risk factors. The purpose of this study has been to find markers to predict the probability of coronary lesion in this group of patients.

PATIENTS AND METHODS

We studied retrospectively a population of 541 patients with valvular heart disease who underwent preoperative coronary angiography from 1989 to 1994. Mean age was 61.8 (range 34-82). There were 301 men and 240 women. We analyzed in each patient different variables such as age, gender, previous angina, hypertension, diabetes mellitus, tobacco and familial predisposition. We correlated these variables with the presence of coronary lesion by multivariate analysis.

RESULTS

There were 73 patients with coronary lesion greater than 50%. The prevalence of significant coronary artery disease was 13.4%. Angina was present in 34.6%. The risk of coronary lesion was defined as odds ratio: previous angina 3.3; tobacco 2.6; diabetes 2.2; hypertension 1.8 and age 1.4. The others variables were not predictor of coronary lesion. The probability of coronary lesion in patients without those variables (angina, tobacco, diabetes, hypertension) was 4%. If we analyzed age, the probability of coronary lesion was 3% in patients under 65 years and 6% above 65 years.

CONCLUSIONS

The lack of previous angina and at least the three risk factors described as predictors of coronary lesion (hypertension, tobacco and diabetes) can define a group of patients with a very low prevalence of coronary lesion, especially if they are under 65 years. It can allow us to avoid preoperatory coronary angiography in patients who undergo valve replacement.

Cardiac operations in octogenarians: perioperative risk factors for death and impaired autonomy

BACKGROUND

With the progressive aging of western populations, cardiac surgeons are increasingly faced with elderly patients.

METHODS

We reviewed the records of 191 consecutive patients aged 80 years or older (mean age, 83 +/- 2.4 years) who underwent a cardiac surgical procedure at our institution from 1991 through 1996.

RESULTS

Ninety-eight patients were men. Preoperatively, 32% of patients were in New York Heart Association class III or IV, and mean left ventricular ejection fraction was 0.55 +/- 0.02. One hundred ten patients (58%) underwent aortic valve replacement, 47 (25%) had coronary artery bypass grafting, 26 (14%) had combined aortic valve replacement and coronary artery bypass grafting, 5 (3%) underwent mitral valve replacement, and 3 (1.6%) had other procedures. Postoperative complications occurred in 69.1% of patients. The hospital mortality rate was 16.2%. Actuarial survival estimates at 1 year, 3 years, and 5 years were 79.2%, 74.9%, and 56.2%, respectively. Multivariate predictors (p < 0.05) of hospital death were preoperative pulmonary hypertension and lower left ventricular ejection fraction. Multivariate predictors of late death were combined aortic valve replacement and coronary artery bypass grafting and female sex. Sixty-four percent of long-term survivors were fully autonomous, and female sex was the only independent predictor of impaired autonomy. Eighty-three percent of survivors were satisfied with their present quality of life.

CONCLUSIONS

Cardiac operations can be performed in octogenarians with a favorable long-term outcome. Earlier referral and intervention is mandatory to improve results in this patient population.

Clinical prediction rules. Applications and methodological standards

The objective of clinical prediction rules is to reduce the uncertainty inherent in medical practice by defining how to use clinical findings to make predictions. Clinical prediction rules are derived from systematic clinical observations. They can help physicians identify patients who require diagnostic tests, treatment, or hospitalization. Before adopting a prediction rule, clinicians must evaluate its applicability to their patients. We describe methodological standards that can be used to decide whether a prediction rule is suitable for adoption in a clinician's practice. We applied these standards to 33 reports of prediction rules; 42 per cent of the reports contained an adequate description of the prediction rules, the patients, and the clinical setting. The misclassification rate of the rule was measured in only 34 per cent of reports, and the effects of the rule on patient care were described in only 6 per cent of reports. If the objectives of clinical prediction rules are to be fully achieved, authors and readers need to pay close attention to basic principles of study design.

Relation of angina pectoris to coronary artery disease in aortic valve stenosis

One hundred three patients with isolated, severe aortic stenosis (AS) were retrospectively analyzed to determine the relation of angina pectoris to angiographically significant coronary artery disease (CAD). All patients underwent coronary angiography regardless of the presence or absence of angina. Angina was significantly associated with CAD (p less than 0.002), with a sensitivity of 78% and a specificity of 53%. However, 25% of the patients without angina had angiographically significant CAD, and in these patients there was a 70% prevalence of 1-vessel disease. Patients with isolated, severe AS should undergo coronary angiography to identify coexistent CAD accurately. The absence of angina does not reliably exclude angiographically significant CAD.

Smoking and coronary artery disease assessed by routine coronary arteriography

The association between extent and duration of smoking habit and severity of coronary atheroma was examined in 387 patients undergoing routine coronary ateriography before valve replacement surgery. Total number of cigarettes smoked in life correlated significantly with severity of coronary artery disease (p less than 0.001) and number of coronary arteries with stenoses of 50% or more (p less than 0.001). Severity of coronary artery disease in current smokers was similar to that in former smokers. Multiple regression analysis showed diastolic blood pressure, cigarette consumption, age, ratio of total cholesterol to high density lipoprotein cholesterol, and history of angina to be the important predictors of severity of coronary artery disease. An estimate of the number of cigarettes smoked in life can be useful in identifying patients with coronary artery disease if used in conjunction with data on other important risk factors.

The significance of psychosocial factors in predicting coronary disease in patients with valvular heart disease

Several prognostic indices for predicting various aspects of coronary artery disease were significantly improved by the inclusion of psychosocial factors. 218 patients with valvular heart disease who had undergone routine coronary arteriography before valve replacement were studied in terms of cigarettes smoked, family history of ischaemic heart disease, HDL:cholesterol ratio, angina, sex, blood pressure and four psychosocial characteristics (i.e. social support, work stress, life events and Type A behavior). It was found that the psychosocial factors improved the preoperative predictive power of significant coronary artery disease on four criteria: previous history of hypertension, previous history of myocardial infarction, signs of peripheral vascular disease and ECG evidence of myocardial infarction.

Prevalence of coronary artery disease in patients with isolated aortic valve stenosis

The prevalence of significant coronary artery disease (reduction in luminal diameter by more than 50%) among 88 consecutive patients with aortic stenosis requiring aortic valve replacement at Hammersmith Hospital was examined. Twenty two (34%) patients had significant coronary disease. Nineteen of 42 (45%) patients with typical angina had coronary disease; three of 20 (15%) patients with atypical chest pain had coronary disease, while none of 26 patients free of chest pain had significant coronary disease. Risk factors for coronary disease were equally distributed among patients with and without significant luminal obstruction. Because of the small, but definite, hazard of coronary arteriography and in the interest of cost containment it is suggested that patients with aortic stenosis who are free of chest pain do not require routine coronary arteriography. This applies particularly to patients requiring urgent aortic valve replacement.