Outcomes of Bilateral Internal Thoracic Arteries in Minimally Invasive Coronary Artery Bypass Grafting With Analogy to the SYNTAX Trial

OBJECTIVES

Minimally invasive CABG is making positive strides in the evolution of coronary artery bypass surgery. We carried out a retrospective study of the efficacy and outcomes of the usage of bilateral internal thoracic arteries in MICS CABG patients over a 6 year period using primary (MACCE) and secondary outcome measures and also carried out a subgroup analysis of patients with diabetes and methodology of revascularization, and with analogy to the SYNTAX trial of the relative risk.

METHODS

Nine hundred and forty patients underwent multivessel MICS CABG via a left mini-thoracotomy from August 2011 to September 2017 and complete revascularization was done using the left internal thoracic artery-right internal thoracic artery Y (LITA-RITA Y) composite conduit. Efficacy and outcomes were evaluated by primary (MACCE) and secondary outcome measures including total length of stay, return to full physical activity, and quality of life. Propensity score matched analyses were carried out in diabetics, in the methodology of revascularization (MICS OPCABG vs. MICS ONCABG), and by comparison to the SYNTAX trial for relative risk. Mean follow-up was 2.9 years (maximum was 5.6 years).

RESULTS

Out of the 940 patients, 843 (89.6%) were diabetic and 97 (10.4%) were nondiabetic. Average grafts were 3.2. There were 9 mortalities (0.9%). The average ICU and hospital stay was 40 ± 12 hours and 3.1 days. Ten patients (1.06%) required reintervention by angioplasty. A total of 99.3% patients were free from major adverse cardiac and cerebrovascular events (MACCE) at follow-up. Mean follow-up was 33 months and 846 (90%) of the patients were followed up. Based on propensity score-matched groups, patients who had their surgery done by MICS ONCABG (beating heart technique) had greater mean number of grafts and hospital length of stay and had significantly longer ICU stay, extubation in OR and blood loss in comparison to patients who had their CABG done by the MICS OPCABG technique. The new technique has shown favorable risk reduction in comparison to both the arms of the SYNTAX trial.

CONCLUSIONS

The safety, efficacy and outcomes of minimally invasive CABG evaluated by primary (MACCE) and secondary outcomes and quality-of-life measures have been good in this study, especially in diabetics, and have shown results better than conventional CABG. The learning curve can be safely negotiated by using peripheral cardiopulmonary bypass assistance and comparison with the SYNTAX trial has shown a relative reduction in all-cause risk.

Patterns of physician use of angiotensin converting enzyme inhibitors in the inpatient treatment of congestive heart failure

Randomized clinical trails have demonstrated that angiotensin-converting enzyme (ACE) inhibitors reduce mortality, improve symptoms, and decrease hospitalization rates in congestive heart failure (CHF) patients with impaired left ventricular systolic function. Guidelines from the Agency for Healthcare Policy and Research (AHCPR) endorse the use of ACE inhibitors in eligible CHF patients and note their underutilization in practice. Randomly selected records of 1,212 Medicare CHF patients in Louisiana, discharged between July 1993 and October 1993, were reviewed. Abstracted data were used to characterize practice patterns and pertinent clinical factors influencing current ACE inhibitor utilization by practicing physicians in eligible Medicare CHF patients admitted to acute care hospitals. A total of 1,133 patients admitted were discharged alive; mean age was 77.6 years (64% female; 68% white). One third of the patients (34%) were already receiving ACE inhibitors on admission; of these, 85% were discharged on ACE inhibitors. The remaining 66% of patients were not on an ACE inhibitor on admission; only 35% of these are documented to have been placed on an ACE inhibitor(s) at discharge. Overall, a significantly large number of CHF patient charts (48%) lacked documentation of LV systolic function assessments. On multivariate logistic regression modeling, the following key clinical variables were positively related to the prescription of ACE inhibitors: low ejection fraction, dyspnea and orthopnea, normal creatinine levels, high diastolic blood pressure, cardiomegaly, and increasing age. Among patients with low ejection fraction, factors contributing to not being discharged on ACE inhibitors included: high creatinine levels, history of myocardial infarction or ischemic heart disease, renal failure, and being African American. This study documents the underutilization of ACE inhibitors in patients with impaired left ventricular systolic function. Results suggest the need for increased physician-based educational efforts concerning the use of ACE inhibitors in CHF patients, and also for increasing left ventricular systolic function assessments and documentation of findings in patient charts.

Addressing issues of face validity in the application of a clinical guideline

In 1995, a statewide project to improve the practice of electroconvulsive therapy (ECT) in the Medicare population was started in Louisiana. A retrospective baseline study found high concurrent utilization of lithium and benzodiazepines, medications considered detrimental to ECT by the second American Psychiatric Association Task Force on ECT. Resistance to a clinical guideline because of lack of face validity by clinicians was used as an opportunity to involve clinicians in using data to evaluate their clinical practices. Results of the first two quarters of the project demonstrated that the strategy was successful.