An assessment of the safety, hemodynamic response, and diagnostic accuracy of commonly used vasodilator stressors in patients with severe aortic stenosis.

BACKGROUND: Increasing numbers of patients are undergoing transcatheter aortic valve replacement, which often involves assessment of coronary artery disease ischemic burden. The safety and diagnostic accuracy of vasodilator stress agents in patients with severe aortic stenosis (AS) undergoing SPECT myocardial perfusion imaging (MPI) has not been established. METHODS: Patients with severe AS (valve area <1 cm2) on echocardiography who underwent vasodilator stress SPECT MPI at two centers were identified. Patients with aortic valve intervention prior to MPI or who underwent concurrent exercise during stress testing were excluded. AS patients were matched to controls without AS based on age, gender, BMI, ejection fraction, and stress agent. Symptoms, serious adverse events, hemodynamic response, and correlation to invasive angiography were assessed. RESULTS: A total of 95 cases were identified with 45% undergoing regadenoson, 31% dipyridamole, and 24% adenosine stress. A significant change in systolic blood pressure (BP), cases vs controls, was observed with adenosine [-17.9 ± 20.1 vs -2.6 ± 24.9 P = .03)], with a trend toward significance with regadenoson [-16.8 ± 20.3 vs -9.4 ± 17.9 (P = .08)] and dipyridamole [-17.8 ± 20.6 vs -9.0 ± 12.1 (P = .05)]. The change in heart rate was significantly different only for adenosine [5.3 ± 16.8 vs 14.2 ± 10.8 (P = .04)]. Overall, 45% of cases vs 24% of controls (P = .004) had a >20 mmHg decrease in systolic BP. Age, BMI, and resting systolic BP were related to a >20 mmHg decrease in systolic BP on univariate analysis, although only higher resting systolic BP was a predictor on multivariate analysis. In 33 patients who underwent angiography, the sensitivity, specificity, and diagnostic accuracy of vasodilator stress MPI was 77%, 69%, and 73%, respectively. No serious adverse events occurred in the severe AS patients. CONCLUSION: Severe AS patients are more likely to have a hemodynamically significant decrease in systolic BP with vasodilator stress. There were no serious adverse events in this severe AS cohort with good diagnostic performance of MPI compared to angiography.

Stress-only Tc-99m myocardial perfusion imaging in an emergency department chest pain unit.

BACKGROUND: Stress-only myocardial perfusion imaging (MPI) saves time by eliminating rest imaging, which is important for emergency department (ED) throughput but has not been studied in an ED population. STUDY OBJECTIVE: To determine the prognosis of a normal stress-only MPI study compared to a normal rest-stress MPI and establish its effectiveness in an ED setting. METHODS: All patients evaluated in the ED over 6.5 years who underwent a stress-only technetium-99m gated MPI were compared to those who had a rest-stress study. All-cause mortality was determined using the Social Security Death Index. Survival was analyzed in patients with normal and abnormal MPI results. RESULTS: A total of 4145 studies (2340 stress-only, 1805 rest-stress) were performed. Patients' average age was 57.9 years, 38.5% were male, and most had an intermediate or low pretest risk of coronary artery disease (87.7%). Average follow-up was 35.9 ± 20.9 months. In patients with normal perfusion, at 1 year of follow-up there were 11 deaths in the stress-only group (0.5% 1-year mortality), and 13 deaths in the rest-stress cohort (1.1% 1-year mortality). At the end of follow-up, the stress-only group had a lower all-cause mortality (p < 0.0001) and similar risk adjusted all-cause mortality (p = 0.10) than the rest-stress cohort. Patients with abnormal perfusion demonstrated the expected differential prognosis based on total perfusion deficits in both groups. CONCLUSIONS: A normal stress-only MPI study has a benign 1-year prognosis similar to a rest-stress study when performed in the ED. The ability to triage patients more rapidly and reduce radiation exposure represents an attractive alternative for low-risk patients.

Tablet-Based Limited Echocardiography to Reduce Sonographer Scan and Decontamination Time during the COVID-19 Pandemic.

BACKGROUND: Limited assessments with handheld ultrasound have found meaningful clinical use in the care of acutely ill patients. However, there are limited data on incorporating handheld-based limited echocardiography into the echocardiography laboratory. The purpose of this study was to assess the efficacy of limited handheld tablet echocardiography as an alternative to traditional echocardiography during the coronavirus disease 2019 (COVID-19) pandemic as a means to limit exposure while providing essential clinical information. METHODS: Ninety consecutive inpatients with known or suspected COVID-19 were scanned according to laboratory COVID-19 guidelines using a limited 11- to 20-clip protocol on a tablet sonograph. The primary assessment was length of study time. Comparison data were drawn from comprehensive echocardiographic examinations ordered on intensive care patients not under COVID-19 precautions. RESULTS: Over a 36-day time period, a total of 91 requests were deemed to be appropriate for echocardiography on patients with suspected or confirmed COVID-19 (average age, 67 years; 64% men; mean body mass index, 32 kg/m2). Of these, 90 (99%) examinations were performed using a handheld device, and all were deemed diagnostic and provided sufficient information for the clinical care team. Sonographer scan time decreased from an average of 24 ± 6.8 min on a traditional platform to 5.4 ± 1.9 min on a tablet. CONCLUSIONS: Limited handheld echocardiography can be successfully implemented in the echocardiography laboratory for screening of COVID-19-related cardiac conditions. The protocol performed with handheld tablet ultrasound provides adequate diagnostic information of major cardiac complications of COVID-19 while decreasing sonographer contact and simplifying decontamination.