Factors affecting mortality after coronary bypass surgery: a scoping review

Objectives

Previous research reports numerous factors of post-operative mortality in patients undergoing isolated coronary artery bypass graft surgery. However, this evidence has not been mapped to the conceptual framework of care improvement. Without such mapping, interventions designed to improve care quality remain unfounded.

Methods

We identified reported factors of in-hospital mortality post isolated coronary artery bypass graft surgery in adults over the age of 19, published in English between January 1, 2000 and December 31, 2019, indexed in PubMed, CINAHL, and EMBASE. We grouped factors and their underlying mechanism for association with in-hospital mortality according to the augmented Donabedian framework for quality of care.

Results

We selected 52 factors reported in 83 articles and mapped them by case-mix, structure, process, and intermediary outcomes. The most reported factors were related to case-mix (characteristics of patients, their disease, and their preoperative health status) (37 articles, 27 factors). Factors related to care processes (27 articles, 12 factors) and structures (11 articles, 6 factors) were reported less frequently; most proposed mechanisms for their mortality effects.

Conclusions

Few papers reported on factors of in-hospital mortality related to structures and processes of care, where intervention for care quality improvement is possible. Therefore, there is limited evidence to support quality improvement efforts that will reduce variation in mortality after coronary artery bypass graft surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01784-z.

Comparison of the Effects of Coronary Artery Bypass Grafting Versus Medical Therapy on Short and Long Term Outcomes in Octogenarian Patients With Multi-Vessel Coronary Artery Disease

Background:

Appropriate treatment methods lead to a reduced rate of mortality and morbidity, and an improved quality of life, in patients with multi-vessel coronary artery disease.

Objectives:

In this study, we compared short and long-term outcomes of coronary artery bypass grafting (CABG) versus medical therapy in patients 80 years of age and older with multi-vessel coronary artery disease (MVCAD).

Patients and Methods:

In this retrospective study, 50 octogenarian patients with MVCAD who underwent CABG were compared with 50 patients in the same condition who were treated with medical therapy during the same time. The primary objective was to compare mortality and morbidity rates, as well as other factors such as the occurrence of chest pain, deterioration of the NYHA functional class, and re-hospitalization, between the two groups. The comparison was made using medical records from the five years post-treatment.

Results:

After five years, the overall mortality rate included 11 patients (22%) in the CABG group versus 18 patients (36%) in the medical therapy group; this difference was not significant between the two groups (P = 0.186). Regarding short-term outcomes, in the CABG group, cardiogenic shock occurred in 9 patients (18%), renal failure in 13 patients (26%), pulmonary complications in 9 patients (18%) and neurologic complications in 3 patients (6%); in the medical therapy group, these same complications occurred, respectively, in 6 patients (12%), 7 patients (14%), 10 patients (20%) and 1 patient (2%). In addition to these factors, freedom from chest pain and improvement in the functional class among the CABG group was significantly higher than among the medical therapy group (P = <0.001).

Conclusions:

CABG may be the superior form of treatment for long-term outcomes in terms of the relief of chest pain, improvement of the functional class, reduced need for re-admission, and later death for octogenarians. However, short-term morbidity may be higher among the CABG group, but the mortality rate after 30 days is quite similar.