Clinical performance of decellularized heart valves versus standard tissue conduits: a systematic review and meta-analysis.

BACKGROUND: Valve replacement surgery is the definitive management strategy for patients with severe valvular disease. However, valvular conduits currently in clinical use are associated with significant limitations. Tissue-engineered (decellularized) heart valves are alternative prostheses that have demonstrated promising early results. The purpose of this systematic review and meta-analysis is to perform robust evaluation of the clinical performance of decellularized heart valves implanted in either outflow tract position, in comparison with standard tissue conduits. METHODS: Systematic searches were conducted in the PubMed, Scopus, and Web of Science databases for articles in which outcomes between decellularized heart valves surgically implanted within either outflow tract position of human subjects and standard tissue conduits were compared. Primary endpoints included postoperative mortality and reoperation rates. Meta-analysis was performed using a random-effects model via the Mantel-Haenszel method. RESULTS: Seventeen articles were identified, of which 16 were included in the meta-analysis. In total, 1418 patients underwent outflow tract reconstructions with decellularized heart valves and 2725 patients received standard tissue conduits. Decellularized heart valves were produced from human pulmonary valves and implanted within the right ventricular outflow tract in all cases. Lower postoperative mortality (4.7% vs. 6.1%; RR 0.94, 95% CI: 0.60-1.47; P = 0.77) and reoperation rates (4.8% vs. 7.4%; RR 0.55, 95% CI: 0.36-0.84; P = 0.0057) were observed in patients with decellularized heart valves, although only reoperation rates were statistically significant. There was no statistically significant heterogeneity between the analyzed articles (I2 = 31%, P = 0.13 and I2 = 33%, P = 0.10 respectively). CONCLUSIONS: Decellularized heart valves implanted within the right ventricular outflow tract have demonstrated significantly lower reoperation rates when compared to standard tissue conduits. However, in order to allow for more accurate conclusions about the clinical performance of decellularized heart valves to be made, there need to be more high-quality studies with greater consistency in the reporting of clinical outcomes.

Normalized end-systolic volume and pre-load reserve predict ventricular dysfunction following surgery for aortic regurgitation independent of body size.

Pre-operative end-systolic volume (ESV) is predictive of outcome after surgery for severe aortic regurgitation. ESV is influenced by body size and reflects function and afterload, but not pre-load. Left ventricular (LV) chamber size and function were measured in 40 patients (ages 10 to 64 years) by echocardiography before and 7 months after operation and expressed as z-scores in addition to simple indexing. A functional pre-load index, a marker of pre-load reserve, was calculated. Independent risk factors for post-operative LV dysfunction included higher post-operative ESV z-score (odds ratio [OR]: 3.3, p = 0.006) and lower functional pre-load index (OR: 0.3, p = 0.03). ESV per square meter had similar power to the ESV z-score. The ESV uncorrected for body size underestimated risk in smaller patients and overestimated risk in larger patients (p < 0.002). Pre-load reserve is an independent risk factor for LV dysfunction after aortic valve surgery in patients with severe aortic regurgitation. Failure to correct ESV for body size introduces systematic bias to risk assessment.

Are two internal thoracic artery grafts as safe as one? Experience from Green Lane Hospital.

AIM: To compare short-term mortality and major morbidity between patients undergoing elective primary isolated CABG with bilateral internal thoracic artery (BITA) or single internal thoracic artery (SITA) grafts at Green Lane Hospital (Auckland, New Zealand). METHODS: We conducted a retrospective study of short-term outcomes in 5955 patients receiving SITA and 637 patients receiving BITA grafts between 1990 and 2004. Only patients undergoing elective primary isolated coronary artery surgery were included. The primary outcome was a composite end-point (early death, perioperative MI, reoperation for sternal wound complications or significantly prolonged hospital stay). Patients receiving BITA grafts were case-matched with patients receiving SITA grafts for confounding factors and comparison was made between perioperative outcomes in the two groups. RESULTS: After case-matching, no statistically significant difference was found in the incidence of our primary endpoint between patients receiving BITA versus SITA grafts [odds ratio 0.84 (95% CI 0.59, 1.21)]. Furthermore, there was no difference in rates of reoperation for sternal wound complications between the two groups [odds ratio 1.00 (95% CI 0.29, 3.44)]. CONCLUSIONS: Given the potential long-term clinical advantages of BITA grafting, our results support the increased use of BITA grafts in selected patients.