Predictors of exercise capacity following septal myectomy in patients with hypertrophic cardiomyopathy.

AIMS: Patients with hypertrophic obstructive cardiomyopathy (HOCM) have impaired exercise capacity. The gold standard therapy for patients with HOCM is septal myectomy surgery; however, changes in maximum oxygen uptake (VO2peak) following myectomy are variable, with VO2peak decreasing in some patients. Therefore, we evaluated changes in VO2peak following surgical myectomy to determine clinical predictors of those exhibiting decreased VO2peak post-myectomy. METHODS: HOCM patients (N = 295) who performed symptom limited cardiopulmonary exercise testing prior to and following surgical myectomy were included for analysis. The VO2peak non-responder group (n = 128) was defined as <0% change in VO2peak from pre- to post-myectomy. Step-wise regression models using demographics, clinical, and physiologic characteristics were created to determine predictors of hypertrophic cardiomyopathy patients in the VO2peak non-responder group. RESULTS: Independent predictors of the VO2peak non-responder group included higher pre-myectomy VO2peak (% predicted), older age, women, history of dyslipidemia, lack of cardiac rehabilitation enrollment, and lower body mass index (all p < 0.03). Forty-three (14.6%) patients reached the primary end-point of all-cause mortality during a median follow up of 11.25 years (interquartile range 6.94 to 16.40). After adjustment for age, sex, beta-blocker use, coronary artery disease history, and body mass index, the VO2peak non-responder group had greater risk of death compared with the VO2peak responder group (adjusted hazard ratio: 1.77, 95% confidence interval: 1.06-3.34, p = 0.01). CONCLUSION: This large hypertrophic cardiomyopathy cohort demonstrated that demographic (i.e. female sex), lack of cardiac rehabilitation enrollment, and cardiovascular risk factors (i.e. history of dyslipidemia) are predictive of those patients that did not exhibit increases in VO2peak following septal myectomy surgery.

A Comparative Analysis of the Injury Patterns and In-Hospital Mortality Rates of Belted and Unbelted Motor-Vehicle Occupants - Puerto Rico, January 2000 to December 2014.

OBJECTIVE: Motor vehicle collisions (MVCs) constitute a leading source of morbidity and mortality worldwide. Seatbelt use has been associated with reduced mortality in MVCs. In Puerto Rico, the impact of seatbelt use on MVC deaths has not been evaluated, although they represent a major public health threat. Therefore, this study aimed to assess the association between seatbelt use and in-hospital mortality at Puerto Rico Trauma Hospital (PRTH). MATERIALS AND METHODS: A retrospective cohort study of 2,685 MVC patients aged 1 to 96 years was conducted using the Trauma Registry at PRTH, with data collected from 2000 through 2014. The patient data included sociodemographic and clinical variables and outcomes. Logistic regression analyses were used to evaluate the mortality risk of patients of severe MVC-related trauma who had been wearing seatbelts and compare it to the risk sustained by their unbelted counterparts. RESULTS: Seatbelt use was more common in females than it was in males (71% vs.62%; p < 0.001) and more prevalent in older as opposed to younger patients (p < 0.001). Belted severe trauma victims suffered less frequently from head injuries than did their unbelted counterparts (p < 0.001). The proportions of patients with Glasgow coma scale (GCS) scores of 8 or lower (17% vs. 6%; p < 0.001) and Injury Severity Scores (ISSs) of 25 or higher (24% vs. 15%; p < 0.001) were greater for the unbelted group. Belted severe trauma victims had a 30% lower in-hospital mortality risk compared to their unbelted peers (ORunadj = 0.70; 95% CI: 0.52-0.92). After adjusting for confounders, this difference in risk was eliminated (ORadj = 1.04; 95% CI: 0.72-1.52). CONCLUSION: Our findings demonstrate that seatbelt use is associated with fewer head injuries, lower ISSs, and higher GCS scores. This suggests that using seatbelts mitigates trauma severity, thereby reducing the likelihood of in-hospital mortality for those MVC victims who were wearing seatbelts at the time of their accident.

Predictors of Exercise Capacity in Patients with Hypertrophic Obstructive Cardiomyopathy.

Hypertrophic obstructive cardiomyopathy (HOCM) patients exhibit compromised peak exercise capacity (VO2peak). Importantly, severely reduced VO2peak is directly related to increased morbidity and mortality in these patients. Therefore, we sought to determine clinical predictors of VO2peak in HOCM patients. HOCM patients who performed symptom-limited cardiopulmonary exercise testing between 1995 and 2016 were included for analysis. Peak VO2 was reported as absolute peak VO2, indexed to body weight and analyzed as quartiles, with quartile 1 representing the lowest VO2peak. Step-wise regression models using demographic features and clinical and physiologic characteristics were created to determine predictors of HOCM patients with the lowest VO2peak. We included 1177 HOCM patients (age: 53 ± 14 years; BMI: 24 ± 12 kg/m²) with a VO2peak of 18.0 ± 5.6 mL/kg/min. Significant univariate predictors of the lowest VO2peak included age, female sex, New York Health Association (NYHA) class, BMI, left atrial volume index, E/e', E/A, hemoglobin, N-terminal pro b-type natriuretic peptide (NT-proBNP), and a history of diabetes, hypertension, stroke, atrial fibrillation, or coronary artery disease. Independent predictors of the lowest VO2peak included age (OR, CI: 1.03, 1.02⁻1.06; p < 0.0001), women (4.66, 2.94⁻7.47; p = 0.001), a history of diabetes (2.05, 1.17⁻3.60; p = 0.01), BMI (0.94, 0.92⁻0.96; p < 0.0001), left atrial volume index (1.07, 1.05⁻1.21; p = 0.04), E/e' (1.05, 1.01⁻1.08; p = 0.004), hemoglobin (0.76, 0.65⁻0.88; p = 0.0004), and NT-proBNP (1.72, 1.42⁻2.11; p < 0.0001). These findings demonstrate that demographic factors (i.e., age and sex), comorbidities (e.g., diabetes and obesity), echocardiography indices, and biomarkers (e.g., hemoglobin and NT-proBNP) are predictive of severely compromised VO2peak in HOCM patients.