Title: Comparison of Shunt Types in the Norwood Procedure for Single-Ventricle Lesions
Topic: Congenital Heart Disease
Date Posted: 5/27/2010
Author(s): Ohye RG, Sleeper LA, Mahoney L, et al., on behalf of the Pediatric Heart Network Investigators.
Citation: N Engl J Med 2010;362:1980-1992.
Clinical Trial: No
Study Question: In patients undergoing single-ventricle palliations, are outcomes better with a modified Blalock-Taussig (MBT) shunt or a right ventricle-to-pulmonary artery (RVPA) shunt?
Methods: A prospective, multicenter, randomized, controlled trial was performed. A total of 549 patients were randomized, with 275 patients receiving an MBT shunt and 274 patients receiving an RVPA shunt. The primary endpoint was death or cardiac transplantation 12 months after randomization. Multiple secondary endpoints were studied, including the need for nonplanned cardiac interventions, RV size and function at 14 months, and transplant-free survival for all enrolled patients until the final enrolled patient reached 14 months of age.
Results: Patients undergoing RVPA shunt at the time of the Norwood procedure had greater transplant-free survival 12 months after randomization (74% as compared with 64% in the MBT shunt group, p = 0.01). Patients undergoing the RVPA shunt had a higher rate of unintended interventions, often attributable to stenting or ballooning of the shunt or branch pulmonary arteries after discharge from the Norwood procedure (p = 0.003). There was no difference in RV size and function between groups at 14 months of age. At longer-term follow-up (mean 32 ± 11 months), the transplant-free survival benefit for the RVPA shunt was no longer significant (p = 0.06).
Conclusions: Transplant-free survival at 12 months is higher with infants undergoing MBT shunt as compared with RVPA shunt at the time of the Norwood procedure, although this difference is no longer significant beyond 12 months of age.
Perspective: This paper reports the results of the first randomized, controlled, multicenter trial comparing two surgical techniques in congenital heart surgery. The benefit of the RVPA shunt over the MBT shunt has been postulated to be improved hemodynamic stability in the early postoperative period because of lack of diastolic runoff and the potential for 'coronary steal.' The concerns for the RVPA shunt have been long-term effects on RV function and PA growth. The MBT shunt was superior for the primary endpoint of death/transplant-free survival at 12 months of age. This effect was no longer significant after extension of follow-up. An extension of the original study is in progress to further understand the intermediate- and long-term differences in outcomes between the two shunt types. This study is extremely important in proving the feasibility of a large-scale, multicenter trial comparing surgical approaches in congenital heart disease, where most studies are limited by sample size and retrospective study design. The study also shows room for further investigation of the multiple practice pattern variations that occur between centers as well as individual surgeons. Such variations may have as much an impact on survival as the type of shunt chosen at the initial surgery. Timothy B. Cotts, M.D., F.A.C.C.
Title: Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus: A Systematic Review and Meta-Analysis
Topic: Prevention/Vascular
Date Posted: 5/27/2010
Author(s): Micha R, Wallace SK, Mozaffarian D.
Citation: Circulation 2010;121:2271-2283.
Clinical Trial: No
Study Question: Is red or processed meat consumption associated with risk for cardiovascular disease and diabetes?
Methods: A systematic review and meta-analysis was performed, which included 1,598 abstracts, of which 20 studies were included (17 prospective cohorts, and 3 case-control studies). Random-effects generalized least squares models of trend estimation were used to derive pooled dose-response estimates.
Results: Of the 20 studies selected, 1,218,380 subjects were included. Cardiovascular events included 23,889 coronary heart disease (CHD) cases, 2,280 strokes, and 10,797 cases of diabetes. Red meat was not associated with heart disease (relative risk [RR] per 100 gram serving per day, 1.00; 95% confidence interval [CI], 0.81-1.23) or diabetes mellitus (RR, 1.16; 95% CI, 0.92-1.46). In contrast, processed meat intake was associated with a significantly increased risk of CHD (RR per 50 gram serving per day, 1.42; 95% CI, 1.07-1.89) and diabetes (RR, 1.19; 95% CI, 1.11-1.27). Associations were intermediate for total meat intake. Only three studies evaluated incidence of stroke and meat consumption. Intake of red meat was not associated with stroke (RR, 1.17; 95% CI, 0.40-3.43); neither were processed meats (RR, 1.14; 95% CI, 0.94-1.39).
Conclusions: The authors concluded that consumption of processed meats, rather than red meats, was associated with increased incidence of heart disease and diabetes.
Perspective: These findings support the importance of a diet low in processed foods. A cardiac healthy diet does not necessarily mean a vegetarian one; however, moderation in consumption of foods such as meat and reductions in processed foods are likely to translate into improved wellness. Elizabeth A. Jackson, M.D., F.A.C.C.