Objective: Global longitudinal strain (GLS) is a sensitive and reproducible predictive factor in patients with ischemic heart disease (IHD), although its correlation with exercise tolerance is unknown. We aimed to identify the correlation between global longitudinal strain (GLS) and cardiopulmonary exercise testing (CPX) parameters and assess the prognostic implications and accuracy of GLS in predicting exercise intolerance in populations with ischemic heart disease (IHD) using CPET criteria. Methods: Prospectively, 108 patients with IHD underwent CPX and 2D speckle-tracking echocardiography. Correlation between GLS and multiple CPX variables was assessed using Spearman’s correlation analysis and univariate regression analysis. A receiver operating characteristic (ROC) curve analysis was performed on GLS to detect exercise intolerance. Results: GLS was correlated with peak oxygen uptake (peak VO₂; r = −0.438, p = 0.000), %PPeak VO₂ (−0.369, p = 0.000), peak metabolic equivalents (METs@peak; r = −0.438, p < 0.01), and the minute ventilation–carbon dioxide production (VE/VCO₂) slope (r = 0.257, p < 0.01). Weak-to-moderate correlations were also identified for the respiratory exchange rate at the anaerobic threshold (RER@AT), end-tidal carbon dioxide at the anaerobic threshold (PETCO₂@AT), oxygen consumption at the anaerobic threshold (VO₂@AT), carbon dioxide production at the anaerobic threshold (VCO₂@AT), and metabolic equivalents at the anaerobic threshold (METs@AT; p < 0.01). On multivariate analysis, the results showed that age, the BMI, and GLS are independent predictors for reduced exercise capacity in patients with IHD (p < 0.01). The area under the ROC curve value of GLS for identifying patients with a peak VO₂ of <14 mL/kg/min was 0.73 (p = 0.000). Conclusion: As a sensitive echocardiographic assessment of patients with ischemic heart disease, global longitudinal strain is an independent predictor of reduced exercise capacity and has a sensitivity of 74.2% and a specificity of 66.7% to detect exercise intolerance.

Objectives: The aim of this study was to identify the differences in the clinical management of shoulder pain by primary care physicians (PCPs) and non-primary care physicians (non-PCPs) from the National Ambulatory Medical Care Survey (NAMCS) dataset. Methods: This cross-sectional study included ambulatory care visits for shoulder pain by using NAMCS data from 2007 to 2019. Descriptive statistics were presented to assess patient-level and visit-level characteristics of the sampled visits. By controlling for patient-level and visit-level covariates, we conducted a multivariable logistic regression to evaluate the influence of primary care physician status on the utilization of health services (pain medications, PT referral, health education/counseling, and diagnostic imaging) for shoulder pain. Results: There were 74.43 million ambulatory care visits by adults with shoulder pain during the study period, and nearly one-third of these shoulder visits were made to PCPs. As compared with non-PCPs, PCPs had higher adjusted odds of prescribing narcotic analgesics (adjusted odds ratio [OR] = 1.62, 95% confidence interval [CI]: 1.04–2.51), skeletal muscle relaxants (adjusted OR = 2.71, 95% CI: 1.65–4.45), other pain medications (adjusted OR = 1.87, 95% CI: 1.13–3.07), and lower odds of prescribing PT (adjusted OR = 0.34, 95% CI: 0.21–0.55) and MRI (adjusted OR = 0.46, 95% CI: 0.25–0.84). Conclusion: We observed significant differences in the services ordered or provided by PCPs versus non-PCPs for shoulder pain in ambulatory care settings. These results may reveal the higher reliance of pharmacological approaches, coupled with the potential under-utilization of PT during the ambulatory shoulder care provided by PCPs compared to non-PCPs in the United States.