Current challenges in three-dimensional bioprinting heart tissues for cardiac surgery.

SUMMARY: Previous attempts in cardiac bioengineering have failed to provide tissues for cardiac regeneration. Recent advances in 3-dimensional bioprinting technology using prevascularized myocardial microtissues as 'bioink' have provided a promising way forward. This review guides the reader to understand why myocardial tissue engineering is difficult to achieve and how revascularization and contractile function could be restored in 3-dimensional bioprinted heart tissue using patient-derived stem cells.

Surgical aortic valve replacement in very elderly patients aged 80 years and over: evaluation of early clinical outcomes.

BACKGROUND: An increasing number of very elderly patients aged ≥80 years will require aortic valve replacement (AVR) for severe aortic stenosis (AS). Many are classified as high-risk surgical candidates. Transcatheter aortic valve implantation (TAVI) has been proposed as an alternative to surgical AVR (SAVR) for high-risk patients. We evaluated early clinical outcomes of very elderly patients undergoing SAVR to optimise TAVI candidate selection. METHODS: We conducted a retrospective case review of 132 consecutive patients aged ≥80 years undergoing isolated SAVR (49 patients) or combined SAVR/CABG (83 patients) during February 2002-January 2010 at a single tertiary referral hospital. Risk for cardiac surgery was calculated using the logistic EuroSCORE (ES(log)). Mortality and morbidity data were collected for the 30-day postoperative period. RESULTS: Thirty-day mortality rate was 8.3% for patients undergoing SAVR (6.1% for isolated SAVR and 9.6% for SAVR/CABG). Permanent stroke occurred in 3.8% and renal insufficiency in 7.6% of the cohort. Thirty-five percent of patients had left ventricular ejection fraction <50%, 67% had advanced symptoms (NYHA class III or IV), and 42% of patients were stratified as high-risk (ES(log)≥20%). CONCLUSIONS: SAVR can be performed in very elderly patients with acceptable operative morbidity and mortality. The outcomes at our institution are comparable to contemporary SAVR and TAVI outcomes.