Research Spotlight

Bilchick, K. C., E. Mejia-Lopez, P. McCullough, K. Breathett, J. L. Kennedy, J. Tallaj, J. Bergin, S. Pamboukian, M. Abuannadi and S. Mazimba (2018). “Clinical Impact of Changes in Hemodynamic Indices of Contractile Function During Treatment of Acute Decompensated Heart Failure.” J Card Fail 24(1): 43-50.

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BACKGROUND: The objective of this work was to determine the impact of improving right ventricular versus left ventricular stroke work indexes (RVSWI vs LVSWI) during therapy for acute decompensated heart failure (ADHF). METHODS AND RESULTS: Cox proportional hazards regression and logistic regression were used to analyze key factors associated with outcomes in 175 patients (mean age 56.7 +/- 13.6 years, 29.1% female) with hemodynamic data from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial. In this cohort, 28.6% and 69.7%, respectively, experienced the outcomes of death, transplantation, or ventricular assist device implantatation (DVADTX) and DVADTX or HF rehospitalization (DVADTXHF) during 6 months of follow-up. Increasing RVSWI (DeltaRVSWI) from baseline to discharge was associated with a decrease in DVADTXHF (hazard ratio [HR] 0.923, 95% confidence interval [CI] 0.871-0.979) per 0.1 mm HgLm(-2) increase); however, increasing LVSWI (DeltaLVSWI) had only a nonsignificant association with decreased DVADTXHF (P = .11) In a multivariable model, patients with DeltaRVSWI 2-fold risk of DVADTXHF (HR 2.05, 95% CI 1.23-3.41; P = .006). CONCLUSION: Compared with left ventricular stroke work, increasing right ventricular stroke work during treatment of ADHF was associated with better outcomes. The results promise to inform optimal hemodynamic targets for ADHF.

Bapat, V., V. Rajagopal, C. Meduri, R. S. Farivar, A. Walton, S. J. Duffy, R. Gooley, A. Almeida, M. J. Reardon, N. S. Kleiman, K. Spargias, S. Pattakos, M. K. Ng, M. Wilson, D. H. Adams, M. Leon, M. J. Mack, S. Chenoweth and P. Sorajja (2018). “Early Experience With New Transcatheter Mitral Valve Replacement.” J Am Coll Cardiol 71(1): 12-21.

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BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a potential therapy for patients with symptomatic, severe mitral regurgitation (MR). The feasibility of this therapy remains to be defined. OBJECTIVES: The authors report their early experience with TMVR using a new valve system. METHODS: The valve is a self-expanding, nitinol valve with bovine pericardial leaflets that is placed using a transapical delivery system. Patients with symptomatic MR who were deemed high or extreme risk by the local heart teams were enrolled in a global pilot study at 14 sites (United States, Australia, and Europe). RESULTS: Fifty consecutively enrolled patients (mean age: 73 +/- 9 years; 58.0% men; 84% secondary MR) underwent TMVR with the valve. The mean Society for Thoracic Surgery score was 6.4 +/- 5.5%; 86% of patients were New York Heart Association functional class III or IV, and the mean left ventricular ejection fraction was 43 +/- 12%. Device implant was successful in 48 patients with a median deployment time of 14 min (interquartile range: 12 to 17 min). The 30-day mortality was 14%, with no disabling strokes, or repeat interventions. Median follow-up was 173 days (interquartile range: 54 to 342 days). At latest follow-up, echocardiography confirmed mild or no residual MR in all patients who received implants. Improvements in symptom class (79% in New York Heart Association functional class I or II at follow-up; p < 0.0001 vs. baseline) and Minnesota Heart Failure Questionnaire scores (56.2 +/- 26.8 vs. 31.7 +/- 22.1; p = 0.011) were observed. CONCLUSIONS: TMVR with the valve was feasible in a study group at high or extreme risk for conventional mitral valve replacement. These results inform trial design of TMVR in lower-risk patients with severe mitral valve regurgitation (Evaluation of the Safety and Performance of the Twelve Intrepid Transcatheter Mitral Valve Replacement System in High Risk Patients with Severe, Symptomatic Mitral Regurgitation - The Twelve Intrepid TMVR Pilot Study.

Bangalore, S., H. G. Bezerra, D. G. Rizik, E. J. Armstrong, B. Samuels, S. S. Naidu, C. L. Grines, M. T. Foster, J. W. Choi, B. D. Bertolet, A. P. Shah, R. Torguson, S. B. Avula, J. C. Wang, J. P. Zidar, A. Maksoud, A. Kalyanasundaram, S. J. Yakubov, B. M. Chehab, A. J. Spaedy, S. P. Potluri, R. P. Caputo, A. Kondur, R. F. Merritt, A. Kaki, R. Quesada, M. A. Parikh, C. Toma, F. Matar, J. DeGregorio, W. Nicholson, W. Batchelor, R. Gollapudi, E. Korngold, R. Sumar, G. S. Chrysant, J. Li, J. B. Gordon, R. M. Dave, G. F. Attizzani, T. P. Stys, O. S. Gigliotti, B. E. Murphy, S. G. Ellis and R. Waksman (2017). “The State of the Absorb Bioresorbable Scaffold: Consensus From an Expert Panel.” JACC Cardiovasc Interv 10(23): 2349-2359.

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Significant progress has been made in the percutaneous coronary intervention technique from the days of balloon angioplasty to modern-day metallic drug-eluting stents (DES). Although metallic stents solve a temporary problem of acute recoil following balloon angioplasty, they leave behind a permanent problem implicated in very late events (in addition to neoatherosclerosis). BRS were developed as a potential solution to this permanent problem, but the promise of these devices has been tempered by clinical trials showing increased risk of safety outcomes, both early and late. This is not too dissimilar to the challenges seen with first-generation DES in which refinement of deployment technique, prolongation of dual antiplatelet therapy, and technical iteration mitigated excess risk of very late stent thrombosis, making DES the treatment of choice for coronary artery disease. This white paper discusses the factors potentially implicated in the excess risks, including the scaffold consideration and deployment technique, and outlines patient and lesion selection, implantation technique, and dual antiplatelet therapy considerations to potentially mitigate this excess risk with the first-generation thick strut Absorb scaffold (Abbott Vascular, Abbott Park, Illinois). It remains to be seen whether these considerations together with technical iterations will ultimately close the gap between scaffolds and metal stents for short-term events while at the same time preserving options for future revascularization once the scaffold bioresorbs.

Ameen, R., S. A. Shemmari and M. Askar (2017). “Next-generation sequencing characterization of HLA in multi-generation families of Kuwaiti descent.” Hum Immunol.

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The frequency of HLA genes in one population may not accurately represent frequencies in other populations. In this study, we characterized extended human leukocyte antigen (HLA) haplotypes in several families of Kuwaiti descent by high-resolution typing using next-generation technology. A total 81 members (including patients and related donors) from 21 families were enrolled. No haplotypes were shared among multiple families. Of 77 haplotypes identified, 23 were not listed in the HaploStats database. Two haplotypes were most common in African Americans, six in Asian Pacific Islanders, three in Caucasians, three in Hispanics, and three in Native Americans. The remaining identified haplotypes were not among the most common 200 HLA haplotypes in any of the five major populations. This cohort had 202 (19%) unique alleles, including 20 rare alleles, 16 very rare alleles, and 2 novel ones. Furthermore, no frequency data were available for 30% (23/77) of the observed haplotypes, and 6% (3/49) of B approximately C blocks identified were not available in the HaploStats database. Kuwaiti individuals carry unique HLA haplotypes that are not shared by the majority of individuals historically reported to the US National Marrow Donor Program registry.

Althans, A. R., J. T. Brady, M. L. Times, D. S. Keller, A. R. Harvey, M. E. Kelly, N. D. Patel and S. R. Steele (2018). “Colorectal Cancer Safety Net: Is It Catching Patients Appropriately?” Dis Colon Rectum 61(1): 115-123.

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BACKGROUND: Disparities in access to colorectal cancer care are multifactorial and are affected by socioeconomic elements. Uninsured and Medicaid patients present with advanced stage disease and have worse outcomes compared with similar privately insured patients. Safety net hospitals are a major care provider to this vulnerable population. Few studies have evaluated outcomes for safety net hospitals compared with private institutions in colorectal cancer. OBJECTIVE: The purpose of this study was to compare demographics, screening rates, presentation stage, and survival rates between a safety net hospital and a tertiary care center. DESIGN: Comparative review of patients at 2 institutions in the same metropolitan area were conducted. SETTINGS: The study included colorectal cancer care delivered either at 1 safety net hospital or 1 private tertiary care center in the same city from 2010 to 2016. PATIENTS: A total of 350 patients with colorectal cancer from each hospital were evaluated. MAIN OUTCOME MEASURES: Overall survival across hospital systems was measured. RESULTS: The safety net hospital had significantly more uninsured and Medicaid patients (46% vs 13%; p < 0.001) and a significantly lower median household income than the tertiary care center ($39,299 vs $49,741; p < 0.0001). At initial presentation, a similar percentage of patients at each hospital presented with stage IV disease (26% vs 20%; p = 0.06). For those undergoing resection, final pathologic stage distribution was similar across groups (p = 0.10). After a comparable median follow-up period (26.6 mo for safety net hospital vs 29.2 mo for tertiary care center), log-rank test for overall survival favored the safety net hospital (p = 0.05); disease-free survival was similar between hospitals (p = 0.40). LIMITATIONS: This was a retrospective review, reporting from medical charts. CONCLUSIONS: Our results support the value of safety net hospitals for providing quality colorectal cancer care, with survival and recurrence outcomes equivalent or improved compared with a local tertiary care center. Because safety net hospitals can provide equivalent outcomes despite socioeconomic inequalities and financial constraints, emphasis should be focused on ensuring that adequate funding for these institutions continues.