Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management.

INTRODUCTION: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. METHODS: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student's t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. RESULTS: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR's < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR's in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. CONCLUSION: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

Risk stratification with vasodilator stress SPECT myocardial perfusion imaging in patients with elevated cardiac biomarkers.

BACKGROUND: Although the diagnostic accuracy and prognostic utility of vasodilator stress MPI have been well established in the non-acute setting, the efficacy of all of the vasodilator stressors in risk stratifying post-MI patients as well as the evaluation of cardiac troponin elevation of unclear etiology is not established. Accordingly, the aim of the present study was to investigate the prognostic efficacy of vasodilator stress MPI in the setting of elevated cardiac troponin to accurately risk stratify these higher-risk patients. METHODS: All patients from two tertiary centers, from 1/1/2010 through 12/31/2012, with elevated cardiac biomarkers within < 7 days and undergoing stress SPECT MPI testing were studied. Results of stress MPI were scored using a 17-segment model based on semiquantitative scoring as normal or abnormal (mild, moderate, or severe) using a total perfusion defect (TPD) of 0%, 1-10%, 10-20%, and > 20%. Mortality data through the year 2014 were obtained from the National Death Index, and survival analyses were performed. The primary endpoint was all-cause mortality with the secondary endpoint being cardiac mortality. RESULTS: A total of 503 patients were followed for an average of 33.6 ± 16.2 months, with a mean age of 69.3 years; 53.7% male; and a majority (88.7%) of them undergoing vasodilator stress. A significant increase in all-cause mortality was seen based on the severity of TPD results for all vasodilators (P < .0001) and regadenoson (P < .0001). Similar prognostic ability was seen for all-cause mortality. This association was maintained even after adjustment for cardiac risk factors, previous coronary disease, and troponin quartiles. MPI results (stress TPD and LVEF) added to traditional cardiac risk factors, and troponin values resulted in a significant incremental increase in the ability to predict all-cause and cardiac mortality, and stress TPD remained independently predictive for both all-cause and cardiac mortality in a multivariate model. CONCLUSION: Vasodilator stress (including regadenoson) MPI effectively risk stratifies patients with recently elevated cardiac biomarkers, with the increasing risk of mortality with the increasing severity of perfusion defects. It provides incremental prognostic value, in addition to clinical factors and degree of troponin elevation.

Correction to: Risk stratification with vasodilator stress SPECT myocardial perfusion imaging in patients with elevated cardiac biomarkers.

The following error (highlighted in bold below) appears in the Results section of the Abstract: A total of 503 patients were followed for an average of 33.6 ± 16.2 months, with a mean age of 69.3 years; 53.7% male; and a majority (88.7%) of them undergoing vasodilator stress. A significant increase in all-cause mortality was seen based on the severity of TPD results for all vasodilators (P < .0001) and regadenoson (P < .0001). Similar prognostic ability was seen for all-cause (this should actually be cardiac) mortality. This association was maintained even after adjustment for cardiac risk factors, previous coronary disease, and troponin quartiles. MPI results (stress TPD and LVEF) added to traditional cardiac risk factors, and troponin values resulted in a significant incremental increase in the ability to predict all-cause and cardiac mortality, and stress TPD remained independently predictive for both all-cause and cardiac mortality in a multivariate model.

Magnesium Levels and Neurologic Outcomes in Patients Undergoing Therapeutic Hypothermia After Cardiac Arrest.

Therapeutic hypothermia (TH) improves neurological outcomes after cardiac arrest by mitigating cerebral reperfusion injury. Serum magnesium (Mg) inhibits glutamate release, restores blood-brain barrier integrity, and decreases brain edema. The neuroprotective role of Mg in cardiac arrest patients undergoing TH is not well established. We analyzed 438 survivors of cardiac arrest who completed a TH protocol from 2008 through 2016. Multivariate and receiver operating characteristic (ROC) analyses examined the association between Mg supplementation and Mg levels before, during, and after TH with neurologic outcomes. Participants were 65.5 ± 15.9 years old, 47% received bystander cardiopulmonary resuscitation, and time to target temperature was 286 ± 196 minutes. Patients with favorable neurologic outcomes had lower Mg levels at presentation (2.1 mg/dL vs. 2.2 mg/dL, p = 0.010; OR [95% CI] = 0.531 [0.329-0.857]) and more frequently received Mg supplementation (39% vs. 25%, p = 0.009; OR [95% CI] = 1.936 [1.171-3.202]). Mg levels on presentation inversely correlated with favorable neurologic outcomes (r = -0.134, p = 0.036). Stratification of patients based on Mg levels demonstrated trends toward worse neurological outcomes at the extremes of the range, though sample sizes were small and the point estimate was not significant. ROC analysis showed no significant Mg level determining favorable outcomes. Mg levels at presentation inversely correlated with neurologic outcomes in cardiac arrest survivors undergoing TH. Intracellular shift and increased renal excretion of Mg may be responsible for the low Mg levels seen in some patients undergoing TH. Whether Mg supplementation could potentiate the beneficial effects of TH remains unclear and deserves further investigation.

Novel Cerebral Protection Technique During Right Transcarotid TAVR in Bicuspid Aortic Stenosis and Porcelain Aorta.

Periprocedural stroke related to transcatheter aortic valve replacement (TAVR) is associated with increased morbidity and mortality. Cerebral embolic protection using the Sentinel device (Claret Medical) has demonstrated reduced rates of stroke during TAVR. However, alternative access such as a transcarotid approach precludes the use of the Sentinel device. We report a case using cerebral embolic protection during a right transcarotid TAVR.