Exertional Heat Stroke at the Boston Marathon: Demographics and the Environment.

PURPOSE: This study aimed to assess associations between exertional heat stroke (EHS) and sex, age, prior performance, and environmental conditions, and report on resources needed for EHS cases at the Boston Marathon. METHODS: We analyzed participant characteristics, environmental data, and EHS medical encounters during the 2015-2019 Boston Marathon races. RESULTS: Among 136,161 starters, there was an incidence of 3.7 EHS cases per 10,000 starters (95% confidence interval, 2.8-4.9), representing 0.5% of all medical encounters. There were significant associations between sex and age (P < 0.0001), sex and start wave (P < 0.0001), and age group and start wave (P < 0.0001). Sex was not significantly associated with increased EHS incidence; however, age younger than 30 yr and assignment to the first two start waves were. All cases occurred at races with average wet bulb globe temperatures of 17°C-20°C. There was a linear correlation between EHS incidence and greater increases in wet bulb globe temperature from start to peak (R2 = 0.7688). A majority of cases (37; 72.5%) were race finishers; nonfinishers all presented after mile 18. Most were triaged 3-4 h after starting, and all were treated with ice water immersion. Treatment times were prolonged (mean (SD), 78.1 (47.5) min; range, 15-190 min); 29.4% (15 cases) developed posttreatment hypothermia, and 35.3% (18 cases) were given intravenous fluids. Most (31 cases; 64.6%) were discharged directly, although 16 cases (33.3%) required hospital transport. There were no fatalities. CONCLUSIONS: Younger and faster runners are at higher risk for EHS at the Boston Marathon. Greater increases in heat stress from start to peak during a marathon may exacerbate risk. EHS encounters comprise a small percentage of race-day medical encounters but require extensive resources and warrant risk mitigation efforts.

Variation in additional testing and patient outcomes after stress echocardiography or myocardial perfusion imaging, according to accreditation status of testing site.

BACKGROUND: The purpose of the present study was to determine whether patients receiving a stress echocardiogram or myocardial perfusion imaging (MPI) test have differences in subsequent testing and outcomes according to accreditation status of the original testing facility. METHODS AND RESULTS: An all-payer claims dataset from Maine Health Data Organization from 2012 to 2014 was utilized to define two cohorts defined by an initial stress echocardiogram or MPI test. The accreditation status (Intersocietal Accreditation Commission (IAC), American College of Radiology (ACR) or none) of the facility performing the index test was known. Descriptive statistics and multivariate regression were used to examine differences in subsequent diagnostic testing and cardiac outcomes. We observed 4603 index stress echocardiograms and 8449 MPI tests. Multivariate models showed higher odds of subsequent MPI testing and hospitalization for angina if the index test was performed at a non-accredited facility in both the stress echocardiogram cohort and the MPI cohort. We also observed higher odds of percutaneous coronary interventions (PCI) performed (OR 1.68, 95% CI 1.13-2.50), if the initial MPI test was done in a non-accredited facility. CONCLUSION: Cardiac testing completed in non-accredited facilities were associated with higher odds of subsequent MPI testing, hospitalization for angina, and PCI.

Pulmonary hypertension subjects exhibit right ventricular transient exertional dilation during supine exercise stress echocardiography.

Pulmonary hypertension is a condition with high morbidity and mortality. Resting transthoracic echocardiography is a pivotal diagnostic and screening test for pulmonary hypertension. The role of exercise stress echocardiography in the diagnosis of pulmonary hypertension is not well-established. We studied right ventricular size changes during exercise using exercise stress echocardiography to assess differences between normal and pulmonary hypertension patients and evaluate test safety, feasibility, and reproducibility. Healthy control and pulmonary hypertension patients performed recumbent exercise using a bicycle ergometer. Experienced echocardiography sonographers recorded the following resting and peak exercise right ventricular parameters using the apical four chamber view: end-diastolic area; end-systolic area; mid-diameter; basal diameter; and longitudinal diameter. Two cardiologists masked to clinical information subsequently analyzed the recordings. Parameters with acceptable inter-rater reliability were analyzed for statistical differences between the normal and pulmonary hypertension patient groups and their association with pulmonary hypertension. We enrolled 38 healthy controls and 40 pulmonary hypertension patients. Exercise stress echocardiography testing was found to be safe and feasible. Right ventricular size parameters were all readily obtainable and all had acceptable inter-observer reliability except for right ventricular longitudinal diameter. During exercise, healthy controls demonstrated a decrease in right ventricular end-systolic area, end-diastolic area, mid-diameter, and basal diameter ( P < 0.05). Conversely, pulmonary hypertension patients demonstrated an increase in right ventricular end-systolic area, end-diastolic area, and mid-diameter ( P < 0.05). These changes were unaffected by multivariate corrections. The sensitivity for pulmonary hypertension of an increase in right ventricular size was 97.2% with a negative predictive value of 95.2%. The ROC C-statistic for increase in right ventricular size was 0.93. This transient exertional dilation (TED) of the right ventricle is observed in pulmonary hypertension patients but not in healthy controls. Recumbent right ventricular exercise stress echocardiography is a feasible and safe diagnostic test for pulmonary hypertension which warrants additional study.

Behavioral Risk Factors and Regional Variation in Cardiovascular Health Care and Death.

INTRODUCTION: Reducing the burden of death from cardiovascular disease includes risk factor reduction and medical interventions. METHODS: This was an observational analysis at the hospital service area (HSA) level, to examine regional variation and relationships between behavioral risks, health services utilization, and cardiovascular disease mortality (the outcome of interest). HSA-level prevalence of cardiovascular disease behavioral risks (smoking, poor diet, physical inactivity) were calculated from the Behavioral Risk Factor Surveillance System; HSA-level rates of stress tests, diagnostic cardiac catheterization, and revascularization from a statewide multi-payer claims data set from Maine in 2013 (with 606,260 patients aged ≥35 years), and deaths from state death certificate data. Analyses were done in 2016. RESULTS: There were marked differences across 32 Maine HSAs in behavioral risks: smoking (12.4%-28.6%); poor diet (43.6%-73.0%); and physical inactivity (16.4%-37.9%). After adjustment for behavioral risks, rates of utilization varied by HSA: stress tests (28.2-62.4 per 1,000 person-years, coefficient of variation=17.5); diagnostic cardiac catheterization (10.0-19.8 per 1,000 person-years, coefficient of variation=17.3); and revascularization (4.6-6.2 per 1,000 person-years; coefficient of variation=9.1). Strong HSA-level associations between behavioral risk factors and cardiovascular disease mortality were observed: smoking (R2=0.52); poor diet (R2=0.38); and physical inactivity (R2=0.35), and no association between revascularization and cardiovascular disease mortality after adjustment for behavioral risk factors (R2=0.02). HSA-level behavioral risk factors were also strongly associated with all-cause mortality: smoking (R2=0.57); poor diet (R2=0.49); and physical inactivity (R2=0.46). CONCLUSIONS: There is substantial regional variation in behavioral risks and cardiac utilization. Behavioral risk factors are associated with cardiovascular disease mortality regionally, whereas revascularization is not. Efforts to reduce cardiovascular disease mortality in populations should focus on prevention efforts targeting modifiable risk factors.

Cardiac Screening in the Noncardiac Surgery Patient.

This article will address common cardiac conditions that require evaluation prior to noncardiac surgery, characterization of urgency and the risk associated with surgical procedures, calculation of preoperative risk assessment, indications for diagnostic testing to quantify cardiac risk, and perioperative strategies to minimize the risk of cardiac complications.

Potential indications for coronary angiography by computed tomography.

Recent advances in computed tomography technology have made possible angiographic images of relatively small, moving vascular structures such as the coronary arteries. Computed tomographic coronary angiography is an exciting modality which has several obvious advantages over invasive catheterization, such as its relatively noninvasive nature and rapid speed of acquisition. However, significant drawbacks still exist, including limitations of spatial and temporal resolution and radiation exposure. Computed tomographic coronary angiography appears best suited as a diagnostic modality for the patient population with a low-to-moderate pretest probability of coronary artery disease, and for specific indications such as the imaging of coronary anomalies and bypass grafts and before biventricular pacemaker placement and atrial fibrillation ablation.

Advances in nuclear imaging for preoperative risk assessment.

Myocardial perfusion imaging (MPI) is frequently utilized for preoperative risk assessment. Results are pertinent for long-term risk. MPI, though most frequently applied in intermediate-risk patients, may also be valuable in selected low- and high-risk individuals. Coronary stenting may alter the timing of noncardiac surgery, which should be considered when performing preoperative risk assessment.

Perioperative and long-term prognostic value of dipyridamole Tc-99m sestamibi myocardial tomography in patients evaluated for elective vascular surgery.

BACKGROUND: Patients with peripheral vascular disease are at increased risk for perioperative and long-term cardiac morbidity and mortality. Substantial data exist supporting the use of preoperative clinical risk stratification and planar thallium myocardial scintigraphy. Only limited data are available assessing the role of technetium-99m (Tc-99m) single photon emission computed tomography (SPECT) for preoperative evaluation in this population. METHODS AND RESULTS: In our study 153 patients who underwent peripheral vascular surgery were followed up for up to 4 years after preoperative dipyridamole Tc-99m sestamibi SPECT to determine clinical and SPECT predictors of perioperative and long-term adverse cardiac events by multivariate analysis. There were no statistically significant clinical or SPECT predictors of perioperative risk, although no perioperative events occurred in patients with normal scans. Abnormality in the left anterior descending (LAD) territory (risk ratio = 3.1; 95% confidence interval, 1.4-7.1) was the only statistically significant univariate predictor of long-term death or myocardial infarction. Only abnormality in the LAD territory appeared to improve model fit beyond clinical risk (risk ratio = 2.9; 95% confidence interval, 1.2-7.3; P =.02). CONCLUSIONS: Patients with normal preoperative scans have a low risk of perioperative cardiac events and may safely undergo peripheral vascular surgery without further coronary intervention. However, scan abnormality in the LAD distribution confers poor long-term prognosis, suggesting that patients with this finding before peripheral vascular surgery should receive aggressive medical therapy and possibly invasive intervention to improve long-term survival.