Chaliki, Hari

Background/Objectives: The peak oxygen consumption (VO2) during cardiopulmonary exercise testing (CPET) is a strong predictor of all-cause mortality. The cardiac output, a key determinant of VO2, can be assessed using resting echocardiographic parameters. The heart rate recovery and ventilatory efficiency (VE/VCO2 slope) from CPET offer additional insights into cardiovascular fitness. Methods: This study aimed to identify resting echocardiographic parameters that predict the percentage of predicted peak VO2, heart rate recovery, and VE/VCO2 slope in a general cardiology population. This retrospective analysis included 1909 patients who underwent echocardiography within 3 months of CPET from 2017 to 2022. Patients with potentially confounding co-morbid conditions were removed. Spearman correlations were used to compare 19 echocardiographic parameters to peak VO2, heart rate recovery, and the VE/VCO2 slope, followed by multiple linear regression of peak VO2. Results: Eleven echocardiographic parameters correlated with peak VO2, with the strongest correlations seen with the left ventricular stroke volume index (R = 0.284, p < 0.001), mitral valve medial annular a’ wave velocity (R = 0.142, p < 0.0001), and mitral E-to-e’ ratio (R = −0.117, p < 0.0001). The left ventricular diastolic parameters and mitral E/A ratio correlated strongly with the heart rate recovery and VE/VCO2 slope. The multiple linear regression analysis identified the left ventricular mass index, stroke volume index, mitral valve E wave velocity, tricuspid valve regurgitation peak systolic velocity, tricuspid lateral annular systolic velocity S’, and left atrial volume index as independent predictors of peak VO2 (R2 = 0.191). Conclusions: The left ventricular stroke volume, diastolic function, and RV systolic function markers are significant predictors of cardiopulmonary fitness, aiding clinical decision-making in patients without CPET data.

Objective To determine the association between serum vitamin D level and left ventricular (LV) diastolic dysfunction. Background Vitamin D deficiency has been shown in observational and prospective studies to be associated with cardiovascular diseases including coronary artery disease, LV hypertrophy and systolic heart failure. Even though diastolic LV dysfunction is an early manifestation of cardiac disease, there is no study that examines whether a deficiency of vitamin D is associated with LV diastolic dysfunction. Method A retrospective observational review of 1011 patients (679 women) was conducted to examine if low 25-OH-vitamin D levels were associated with LV diastolic dysfunction. Results All the LV diastolic dysfunction parameters: left atrial volume index, E/e', e' velocity, LV mass index and deceleration time were not significantly different between patients with 25-OH vitamin D level ≤20 ng/mL vs 25-OH vitamin D level >20 ng/mL. Conclusions Despite growing medical literature suggesting vitamin D deficiency is associated with cardiovascular disease, in this present study there is no significant association of vitamin D levels and LV diastolic performance, including left atrial volume index.