CABG in patients with left ventricular dysfunction

Is the world ready for the STICH 3.0 trial?

PURPOSE OF REVIEW

Coronary artery disease (CAD) is responsible for >50% of heart failures cases. Patients with ischemic left ventricular systolic dysfunction (iLVSD) are known to have poorer outcomes after percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) compared to patients with a normal ejection fraction. Nevertheless, <1% of patients in coronary revascularization trials to date had iLVSD. The purpose of this review is to describe coronary revascularization modalities in patients with iLVSD and highlight the need for randomized controlled trial evidence comparing these treatments in this patient population.

RECENT FINDINGS

Network meta-analytic findings of observational studies suggest that PCI is associated with higher rates of mortality, cardiac death, myocardial infarction, and repeat revascularization but not stroke compared to CABG in iLVSD. In recent years, outcomes for patients undergoing PCI have improved as a result of advances in technologies and techniques.

SUMMARY

The optimal coronary revascularization modality in patients with iLVSD remains unknown. In observational studies, CABG appears superior to PCI; however, direct randomized evidence is absent and developments in PCI techniques have improved post-PCI outcomes in recent years. The Surgical Treatment for Ischemic Heart Failure 3.0 consortium of trials will seek to address the clinical equipoise in coronary revascularization in patients with iLVSD.

Ischaemia change with revascularisation versus medical therapy in reduced ejection fraction

Objective

Nuclear imaging data demonstrate that revascularisation leads to favourable effects on ischaemia burden and improved outcomes compared with medical therapy (MT). In patients with heart failure (HF), the effects of MT versus revascularisation on ischaemia change and its independent prognostic significance requires investigation.

Methods

From the Duke Databank, we performed a retrospective analysis of 278 consecutive patients with coronary artery disease (CAD) and ejection fraction (EF) ≤40%, who underwent 2 serial myocardial perfusion scans between 1993 and 2009. Ischaemia change was calculated for patients undergoing MT alone, or revascularisation. Cox proportional hazards regression modelling was used to identify factors associated with death/myocardial infarction (MI).

Results

The magnitude of ischeamia reduction was greater with revascularisation than with MT alone (median change of −6% vs 0%, p<0.001). With revascularisation, more patients experienced ≥5% ischaemia reduction compared with MT (52% vs 25%, p<0.01) and a similar percentage experienced ≥5% ischaemia worsening (13% vs 18%, p=0.37). After risk adjustment, ≥5% ischaemia worsening was associated with decreased death/MI (HR=0.58; 95% CI 0.36 to 0.96).

Conclusions

In patients with HF with CAD, revascularisation improves long-term ischaemia burden compared with MT. Ischaemia worsening on nuclear imaging was associated with reduced risk of death/MI, potentially related to development of ischaemic viable myocardium as opposed to scar tissue.

Coronary artery bypass surgery in patients with low EuroSCORE preoperative risk

Patients with EuroSCORE <2 are usually considered to have a low surgical risk and the lowest mortality. In our study preoperative factors in a group of 250 consecutive low-risk patients (EuroSCORE<2), who underwent first isolated coronary artery by-pass surgery during 1999 and 2000., were analyzed. Cumulative follow-up period was 1178.48 patient-years and the primary clinical outcome was all-cause mortality. Patients’ average age was 59.2±7.5 yr. The following preoperative risk factors of increased 5-year mortality were identified: older age (P<0.001), smoking, prior non-recent myocardial infarction and reinfarction, anteroseptal localization of myocardial infarction (P<0.001), poor ejection fraction<=35% (P<0.001), dilatative cardiomyopathy (P<0.001), wall motion systolic index 〉2 (P<0.001), left atrial dilatation (P<0.001), mitral regurgitation more than 2+ (P<0.001), presence of left main disease, triple vessel coronary artery disease (P<0.001), absence of collaterals (P<0.001) and presence of more than 3 distal anastomoses. Through the present study it has been shown that it is possible to identify a subgroup of patients with low operative mortality and excellent 5-year survival after surgical treatment for coronary artery bypass surgery using preoperative clinical, echocardiographic, coronarographic and intraoperative data, even in difficult conditions of the civil war in the region.