Risk Score for Predicting Long-Term Mortality After Coronary Artery Bypass Graft Surgery

Abstract

Background No simplified bedside risk scores have been created to predict long-term mortality after coronary artery bypass graft (CABG) surgery. Methods and Results The New York State’s Cardiac Surgery Reporting System was used to identify 8,597 patients who underwent isolated CABG surgery in July-December 2000. The National Death Index was used to ascertain patients’ vital status through December 31, 2007. A Cox proportional hazards model was fit to predict death following CABG surgery using pre-procedural risk factors. Then points were assigned to significant predictors of death based on the values of their regression coefficients. For each possible point total, the predicted risks of death at years 1, 3, 5, and 7 were calculated. It was found that the 7-year mortality rate was 24.2% in the study population. Significant predictors of death included age, body mass index, ejection fraction, unstable hemodynamic state or shock, left main coronary artery disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes, renal failure, and history of open heart surgery. The points assigned to these risk factors ranged from 1 to 7; and possible point totals for each patient ranged from 0 to 28. The observed and predicted risks of death at years 1, 3, 5, and 7 across patient groups stratified by point totals were highly correlated. Conclusions The simplified risk score accurately predicted the risk of mortality following CABG surgery, and can be used for informed consent and as an aid in determining treatment choice.

Long‐Term Post‐CABG Survival: Performance of Clinical Risk Models Versus Actuarial Predictions

“…Upon closer review, the Hannan model was seen to be most accurate for risk predictions for the subgroup of patients ≤50 years of age. This supports Wu et al's statement that their model is useful “…for informed consent and as an aid in determining treatment choice,”6 but suggests the model's greatest strength may lie in its accuracy in providing long‐term mortality estimates for younger or sicker patients. The Hannan model was not designed to be specific for cardiac‐related deaths only; therefore, no comment can be made on the likely distribution of non‐cardiac versus cardiac‐related causes of death in our patient sample.…”

“…No confidence intervals were calculated for the Hannan O/E ratios, however, as the values of these confidence intervals were not published with the point estimates given in the Wu et al publication 6. For further reference, all observed mortality proportions and models' predicted mortality probabilities are listed in Supplementary Table 2.…”

Obesity is still a risk factor in coronary artery bypass surgery

“…Wigfield et al (14) also documented similar results, but they reported an increase in rates of complications like prolonged ventilation and acute renal failure without hemodialysis. Conversely, Wu et al (15) reported that obesity was an independent risk factor for mortality in long term followup after coronary bypass surgery. We documented that the mortality rates were similar in both groups.…”

Die Nieren im Umfeld von Organschäden

“…Besonders deutlich wird dies am stark erhöhten kardiovaskulären Risiko bei Patienten mit chronischer Nierenkrankheit. Für kardiovaskuläre Erkrankungen stellt die chronische Nierenkrankheit einen der wesentlichen Risikofaktoren noch vor dem Diabetes mellitus dar [1]. Allerdings können auch Funktionsstörungen anderer Organe die Funktion der Niere beeinträchtigen.…”