Cardiology

Alvarez Villela, M., C. Y. Guerrero-Miranda, T. Chinnadurai, S. R. Patel and U. P. Jorde (2019). “Rate Response Pacing in Left Ventricular Assist Device Patients.” ASAIO Journal Mar 19. [Epub ahead of print].

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Chronotropic incompetence (II) is common in advanced heart failure and is associated with worse functional capacity. This impaired heart rate (HR) response during exercise is ameliorated but persists after left ventricular assist device (LVAD) implantation. Patients with continuous flow LVAD (CF-LVAD) suffer from significant exercise limitation despite restoration of resting cardiac output. Whether CI contributes to exercise limitation in this setting is unknown. We examined the role of CI and the effect of rate response pacing (RRP) on functional capacity in a group of stable patients with LVAD . . . Our findings demonstrate the association between CI and poor functional capacity in patients with advanced heart failure and CF-LVAD, in line with one small prior study. Findings in this cohort point out the inadequacy of current RRP technologies for sensing signals other than atrial rate during different types of physical activity. When RRP increased the HR promptly and in a sustained manner, replicating the activity of the sinus node, the effect on aerobic capacity was substantial, but this occurred in only a minority of patients. In contrast to the heterogeneous effect of RRP during treadmill-based CPX, its effect on 6 MWD was more homogeneous. This could represent a difference in CIED sensing efficacy since all of the employed devices in this study have an accelerometer-based RRP system. Ambulation, producing linear displacement of the body during 6 MWT could be more easily sensed by accelerometer-based systems than the more static motion during treadmill exercise. These findings warrant further exploration to allow for improvement of current RRP technologies. An efficacious sensing system that can replicate sinus nodal function during different types of physical and emotional activity may lead to important improvements in the quality of life of the growing durable CFLVAD population. (Excerpt from text, p. 1-2; no abstract available.)E

Vemulapalli, S., J. D. Carroll, M. J. Mack, Z. Li, D. Dai, A. S. Kosinski, D. J. Kumbhani, C. E. Ruiz, V. H. Thourani, G. Hanzel, T. G. Gleason, H. C. Herrmann, R. G. Brindis and J. E. Bavaria (2019). “Procedural Volume and Outcomes for Transcatheter Aortic-Valve Replacement.” N Engl J Med Apr 3. [Epub ahead of print].

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BACKGROUND: During the introduction of transcatheter aortic-valve replacement (TAVR) in the United States, requirements regarding procedural volume were mandated by the Centers for Medicare and Medicaid Services as a condition of reimbursement. A better understanding of the relationship between hospital volume of TAVR procedures and patient outcomes could inform policy decisions. METHODS: We analyzed data from the Transcatheter Valve Therapy Registry regarding procedural volumes and outcomes from 2015 through 2017. The primary analyses examined the association between hospital procedural volume as a continuous variable and risk-adjusted mortality at 30 days after transfemoral TAVR. Secondary analysis included risk-adjusted mortality according to quartile of hospital procedural volume. A sensitivity analysis was performed after exclusion of the first 12 months of transfemoral TAVR procedures at each hospital. RESULTS: Of 113,662 TAVR procedures performed at 555 hospitals by 2960 operators, 96,256 (84.7%) involved a transfemoral approach. There was a significant inverse association between annualized volume of transfemoral TAVR procedures and mortality. Adjusted 30-day mortality was higher and more variable at hospitals in the lowest-volume quartile (3.19%; 95% confidence interval [CI], 2.78 to 3.67) than at hospitals in the highest-volume quartile (2.66%; 95% CI, 2.48 to 2.85) (odds ratio, 1.21; P = 0.02). The difference in adjusted mortality between a mean annualized volume of 27 procedures in the lowest-volume quartile and 143 procedures in the highest-volume quartile was a relative reduction of 19.45% (95% CI, 8.63 to 30.26). After the exclusion of the first 12 months of TAVR procedures at each hospital, 30-day mortality remained higher in the lowest-volume quartile than in the highest-volume quartile (3.10% vs. 2.61%; odds ratio, 1.19; 95% CI, 1.01 to 1.40). CONCLUSIONS: An inverse volume-mortality association was observed for transfemoral TAVR procedures from 2015 through 2017. Mortality at 30 days was higher and more variable at hospitals with a low procedural volume than at hospitals with a high procedural volume. (Funded by the American College of Cardiology Foundation National Cardiovascular Data Registry and the Society of Thoracic Surgeons.).

Thourani, V. H., S. M. O’Brien, J. J. Kelly, D. J. Cohen, E. D. Peterson, M. J. Mack, D. M. Shahian, F. L. Grover, J. D. Carroll, J. M. Brennan, J. Forcillo, S. V. Arnold, S. Vemulapalli, S. Fitzgerald, D. R. Holmes, J. E. Bavaria and F. H. Edwards (2019). “Development and Application of a Risk Prediction Model for In-Hospital Stroke After Transcatheter Aortic Valve Replacement: A Report From The Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.” Ann Thorac Surg 107(4): 1097-1103.

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BACKGROUND: Stroke is a serious complication after transcatheter aortic valve replacement (TAVR), yet predictive models are not available. A new risk model for in-hospital stroke after TAVR was developed and used to estimate site-specific performance. METHODS: We included 97,600 TAVR procedures from 521 sites in The Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry from July 2014 to June 2017. Association between baseline covariates and in-hospital stroke was estimated by logistic regression. Discrimination was evaluated by C-statistic. Calibration was tested internally via cross-validation. Hierarchical modeling was used to estimate risk-adjusted site-specific performance. RESULTS: Median age was 82 years, 44,926 (46.0%) were women, and 1,839 (1.9%) had in-hospital stroke. Covariates associated with stroke (odds ratio) included transapical access (1.44), access excluding transapical and transfemoral (1.77), prior stroke (1.57), prior transient ischemic attack (1.50), preprocedural shock, inotropes or mechanical assist device (1.48), smoking (1.28), porcelain aorta (1.23), peripheral arterial disease (1.21), age per 5 years (1.11), glomerular filtration rate per 5 mL/min (0.97), body surface area per m(2) (0.55 male; 0.43 female), and prior aortic valve (0.78) and nonaortic valvular (0.42) procedures. The C-statistic was 0.622. Calibration curves demonstrated agreement between observed and expected stroke rates. Hierarchical modeling showed 10 (1.9%) centers with significantly higher odds ratios for in-hospital stroke than their peers. CONCLUSIONS: A risk model for in-hospital stroke after TAVR was developed from The Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry and used to estimate site-specific stroke performance. This model can serve as a valuable resource for quality improvement, clinical decision making, and patient counseling.

Sorajja, P., N. Moat, V. Badhwar, D. Walters, G. Paone, B. Bethea, R. Bae, G. Dahle, M. Mumtaz, P. Grayburn, S. Kapadia, V. Babaliaros, M. Guerrero, L. Satler, V. Thourani, F. Bedogni, D. Rizik, P. Denti, N. Dumonteil, T. Modine, A. Sinhal, M. L. Chuang, J. J. Popma, P. Blanke, J. Leipsic and D. Muller (2019). “Initial Feasibility Study of a New Transcatheter Mitral Prosthesis: The First 100 Patients.” J Am Coll Cardiol 73(11): 1250-1260.

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BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a rapidly evolving therapy. Follow-up of TMVR patients remains limited in duration and number treated. OBJECTIVES: The purpose of this study was to examine outcomes with expanded follow-up for the first 100 patients who underwent TMVR with the prosthesis. METHODS: The Global Feasibility Study enrolled symptomatic patients with either primary or secondary mitral regurgitation (MR) who were at high or prohibitive surgical risk. The present investigation examines the first 100 patients treated in this study. Clinical outcomes through last clinical follow-up were adjudicated independently. RESULTS: In the cohort (mean age 75.4 +/- 8.1 years; 69% men), there was a high prevalence of severe heart failure symptoms (66%), left ventricular dysfunction (mean ejection fraction 46.4 +/- 9.6%), and morbidities (Society of Thoracic Surgeons Predicted Risk of Mortality, 7.8 +/- 5.7%). There were no intraprocedural deaths, 1 instance of major apical bleeding, and no acute conversion to surgery or need for cardiopulmonary bypass. Technical success was 96%. The 30-day rates of mortality and stroke were 6% and 2%, respectively. The 1-year survival free of all-cause mortality was 72.4% (95% confidence interval: 62.1% to 80.4%), with 84.6% of deaths due to cardiac causes. Among survivors at 1 year, 88.5% were New York Heart Association function class I/II, and improvements in 6-min walk distance (p < 0.0001) and quality-of-life measurements occurred (p = 0.011). In 73.4% of survivors, the Kansas City Cardiomyopathy Questionnaire score improved by >/=10 points. CONCLUSIONS: In this study of TMVR, which is the largest experience to date, the prosthesis was highly effective in relieving MR and improving symptoms, with an acceptable safety profile. Further study to optimize the impact on long-term survival is needed.

Shutze, W. P., Sr., R. Shutze, P. Dhot, M. Forge, A. Salazar and G. O. Ogola (2019). “Sex as an independent risk factor for long-term survival after endovascular aneurysm repair.” J Vasc Surg 69(4): 1080-1089.e1081.

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BACKGROUND: Several vascular surgical procedures, including repair of abdominal aortic aneurysms (AAAs), show poorer outcomes for women than for men. We evaluated the impact of sex-based demographic differences on survival after endovascular aneurysm repair (EVAR). METHODS: We reviewed EVARs performed at our institution between 2003 and 2009 and assessed aortic neck variables (length, diameter, angulation, and calcification), iliac artery variables (length, tortuosity, angulation, and calcification), and AAA diameter. Cox proportional hazards models were used to examine the association between sex and 5-year mortality while adjusting for patients’ demographics, comorbidities, anatomic variables, and AAA parameters. The final model adjusted for sex, age, body mass index, hypertension, iliac artery length, and aortic neck length. RESULTS: Of 336 patients, 278 were male (mean age, 73 years) and 58 were female (mean age, 77 years; P = .0005). Men had more coronary artery bypass grafts (79 vs 8; P = .02) and percutaneous coronary interventions (52 vs 4; P = .03) than women did. Significant differences between the sexes was seen for aortic neck angle, diameter, and length and for iliac artery diameter and length. Men (44%) were more likely than women (22%; P = .0002) to have EVAR performed within the device guidelines. Five-year survival was 73% in men and 49% in women. Multivariable analysis showed that female sex, increase in age, low body mass index (<25 kg/m(2)), and aortic neck length were significantly associated with risk of 5-year mortality. CONCLUSIONS: Women presented at an older age and with a more hostile anatomy. They had reduced survival compared with men after EVAR. After controlling for comorbidities and aortic neck and iliac artery anatomy, sex remained an independent predictor for survival.