Defining the blanking period, using continuous ECG monitoring, after cryoballoon pulmonary vein isolation.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. A blanking period (BP) of 3 months is used in clinical trials and practice. However, the optimal BP duration after PVI remains undefined. OBJECTIVE: The aim of this study was to objectively define, using continuous monitoring by an implantable loop recorder, the optimal BP duration after cryoballoon PVI. METHODS: We enrolled consecutive patients who had cryoballoon PVI and an implantable loop recorder. We determined the time of the last confirmed episode of AF within the blanking period. This was then correlated with AF recurrence in the first year after ablation. RESULTS: There were 210 patients (66 ± 9 years; 138 [66%] male; 116 [55%] paroxysmal AF; CHA2DS2-VASc score, 2.5 ± 1.6). We defined 4 distinct groups based on the last AF episode within the BP: no AF days 0-90 (n = 96 [46%]) and last AF 0-30 days (n = 46 [22%]), 31-60 days (n = 18 [9%]), and 61-90 days (n = 50 [24%]). After the 3-month BP, 101 (48%) patients had AF recurrence at 160 ± 86 days. Compared with patients with no AF in the BP, those with recurrent AF and AF burden >0% 30 days after ablation had a significantly greater AF recurrence during long-term follow-up (P = .001). CONCLUSION: Our data show that the approximately one-third of patients in whom AF occurs and who have a burden of >0% after the first month that follows PVI are at significantly higher risk of long-term recurrent AF. We therefore suggest that the blanking period be limited to a month after cryoballoon PVI.

The Danish-American Research Exchange (DARE): a cross-sectional study of a binational research education program.

BACKGROUND: Most medical educational programs emphasize clinical observation or clinical skill acquisition, fewer focus upon research. The Danish-American Research Exchange (DARE) program, sponsored by the Lundbeck Foundation, is unique in that the medical student initiates biomedical research collaboration between Danish and US medical institutions. To achieve this, Danish medical students (DARE students) conduct binational mentored research projects while based in the United States for 10 months. In addition, DARE students are introduced to interdisciplinary thinking about how to develop ultra-low-cost healthcare interventions through the '$10 Challenge'. METHODS: We conducted a cross-sectional study of DARE alumni over five consecutive years (2015-2020, n = 24). Research metrics included completion of a research project, primary authorship, and co-authorship of publications. The number of publications, prior to and after the DARE program were enumerated. For the first four cohorts, graduation from medical school and acceptance or intention to enter a joint MD-PhD program also were assessed. Two focus groups were conducted using constructivist grounded theory. Discussions were transcribed, redacted, and coded using Dedoose software. RESULTS: DARE Medical students were 31.2 years (range 24-35), the majority were women (67%;16/24). The majority (17/24;71%) completed a first author publication in a peer-reviewed journal with a median of 3.9 per DARE alumnus. DARE alumnus reported increased proficiency in biostatistics, epidemiology, coding and public speaking as well as stronger research qualities in creativity, critical thinking, comfort in approaching scientist in both the US and Denmark (p < 0.001 for all). Qualitative key themes included: increased confidence, a deepening of research inquiry and linkage to a research network. CONCLUSIONS: Preliminarily, this study suggests that medical students can initiate binational collaboration in medicine. Benefits include research productivity, intention to pursue academic medical careers, as well as positive impacts on motivation. This medical student-initiated research model lays the groundwork for using this model across other country pairs to promote binational collaboration.

Left ventricular end-systolic volume response post-stress echocardiography: Dilation as a marker of multi-vessel coronary artery disease.

BACKGROUND: Transient ischemic dilation of the left ventricle (LV) during stress echocardiography indicates extensive myocardial ischemia. It remains unclear whether the change of LV end-systolic volume (ESV) or end-diastolic volume (EDV) better correlated with significant coronary artery disease (CAD). Meanwhile, the clinical significance of the extent of the volumetric change post-stress has not been investigated. METHODS: One hundred and five individuals (62 ± 12 years and 75% men) who underwent coronary angiography following exercise treadmill echocardiography were enrolled retrospectively. An additional 30 age- and sex-matched healthy subjects were included for comparison. LV dilation was defined as any increase in LV volume from rest to peak exercise. Patients who had at least two coronary arteries with significant stenosis were considered as having multi-vessel CAD. RESULTS: Thirty-four patients had ESV dilation during exercise echocardiography. On the contrary, ESV decreased at peak exercise in all healthy subjects. Forty-one patients had multi-vessel CAD, and its prevalence was higher in patients with ESV dilation (65% vs 27%, p = 0.001). The extent of ESV increase correlated with CAD severity. ESV dilation is associated with multi-vessel CAD (Odds ratio [OR] 5.02, 95% confidence interval [CI] 2.09 - 12.07, p < 0.001). After adjustment for EDV increase, clinical, electrocardiographic, and echocardiographic variables, the association remained significant (adjusted OR 5.57, 95% CI 1.37-22.64; p = 0.02). CONCLUSIONS: ESV dilation independently correlated with multi-vessel CAD, whereas EDV dilation did not. The amount of ESV increase correlated with the severity of CAD. Our findings provide a rationale for incorporating volume measurements into stress echocardiography practice.

Factors associated with non-survival from in-hospital maternal cardiac arrest: An analysis of Get With The Guidelines® (GWTG) data.

INTRODUCTION: Maternal mortality has risen in the United States during the 21st century. Factors influencing outcome of maternal cardiac arrest (MCA) remain largely unexplored. OBJECTIVE: We sought to further elucidate the factors affecting maternal death from in-hospital (IH) MCA. METHODS: Our query of the American Heart Association's GWTG®-Resuscitation voluntary registry from 2000-2017 revealed 561 index cases of IH MCA with complete outcome data. Logistic regression was performed using hospital death as the primary outcome and included variables with a p value = 0.1 or less based upon univariate analysis. Age, race, year of arrest, pre-existing conditions, first documented pulseless rhythm and location of arrest were used in the model. Sensitivity analyses and assessment of variable interaction were also performed to test model stability. Institutional review deemed this research exempt from ethical approval. RESULTS: Among 561 cases of MCA, 57.2% (321/561) did not survive to hospital discharge. IH death was not associated with maternal age, race and year of event. In the final model, IH death was significantly associated with pre-arrest hypotension/hypoperfusion (OR = 1.80 (95% CI, 1.16-2.79); p = 0.009). The occurrence of MCA outside of the delivery suite (referent group) or operating room was associated with a significantly higher risk of death: ICU/Post-Anesthesia Care Unit (PACU) (OR = 3.32 (95% CI, 2.00-5.52); p < 0.001) and ER/other (OR = 1.89 (95% CI, 1.15-3.11); p = 0.012). While MCA cases with a shockable vs. non-shockable first documented pulseless rhythm had similar outcomes, those with an indeterminate rhythm were less likely to die, (OR = 0.41(95% CI, 0.20-0.84); p = 0.014). In a sensitivity analysis, removal of the indeterminate group did not alter outcomes regarding first documented pulseless rhythm or arrest location. Area under the curve for the final model was 0.715 (95% CI 0.673-0.757). CONCLUSIONS: Our study identified several novel factors associated with IH death of our MCA cohort. More research is required to further understand the pathophysiologic dynamics affecting outcomes of IH MCA in this unique population.

Comparative Analysis Following Implementation of Two Types of Y-Composite Multiarterial Revascularization Strategies at a Single Academic Institution.

Background We compared early outcomes, at a single academic institution, of implementing full coronary revascularization in coronary artery bypass grafting using multiarterial Y-composite grafts with multiple sequential anastomoses. Methods and Results Clinical records of 425 consecutive patients who underwent coronary artery bypass grafting using Y-grafting with left internal mammary artery and radial artery (Y-RA group) or right internal mammary artery (Y-RIMA group) from 2015 to 2019, were reviewed. These were compared with the institutional experience of isolated coronary artery bypass grafting cases (in situ on pump/off pump) for the same period of time. When comparing the 4 groups, the Y-RIMA/RA groups revealed a higher number of distal anastomosis than the in situ on- or off-pump groups. When the number of distal arterial anastomosis was analyzed, there was a superiority of using the Y-configuration compared with the in situ approach. Moreover, there were no significant differences among groups for mortality and/or major adverse cardiac and cerebrovascular events in hospital or at 30-day follow-up. A subanalysis comparing the Y-RIMA group with the Y-RA group showed that complementary grafts to the Y-construct were required to accomplish full revascularization more frequently in the Y-RIMA group. Full-arterial revascularization was achieved in 92.2% of the Y-RA group and 72.0% of the Y-RIMA group (P<0.001). In 82.8% of the Y-RA group and 30.8% of the Y-RIMA group, revascularization was completed as an anaortic procedure (P<0.001). Conclusions The 2 types of arterial Y-composite grafting were able to be introduced in the routine practice of our institution showing comparable results to the established institutional practice. This procedure allowed for more arterial distal anastomosis to be performed safely without compromising outcomes.

Incidence and Predictors of Very Late Recurrence of Atrial Fibrillation Following Cryoballoon Pulmonary Vein Isolation.

BACKGROUND: A very late recurrence (VLR) of atrial fibrillation (AF) is considered present when the first recurrence of AF occurs ≥12 months following ablation. Prior studies characterizing VLR have not used an implantable loop recorder for ECG monitoring. Thus, it is unknown whether VLR truly occurs or whether these patients have simply had unrecognized AF. Our objective was to assess the incidence and predictors of VLR in patients who underwent cryoballoon pulmonary vein isolation alone, had an implantable loop recorder, and were confirmed AF free for at least 1 year. METHODS: We enrolled consecutive patients with paroxysmal or persistent AF who underwent cryoballoon pulmonary vein isolation and had an implantable loop recorder implanted <3 months post-ablation. Patients free of AF 1 year post-ablation were followed prospectively for recurrent AF. All AF episodes were adjudicated. RESULTS: We included 188 patients (66±10 years; 116 [62%] men; 102 [54%] paroxysmal AF; CHA2DS2-VASc, 2.6±1.7). After 1 year post-pulmonary vein isolation, 93 (49%) patients remained AF free. During subsequent follow-up, 30 (32%) patients had VLR of AF. The only independent risk factor for VLR was an elevated CHA2DS2-VASc score (hazard ratio, 1.317 [95% CI, 1.033-1.6979]; P=0.026). Patients with CHA2DS2-VASc score ≥4 represented a quarter of the population and were at the highest risk. CONCLUSIONS: Our data using implantable loop recorders for continuous ECG monitoring post-AF ablation show that VLR occurs in a third of patients after an apparently successful cryoballoon pulmonary vein isolation procedure. Additional strategies are needed to ensure long-term freedom from AF recurrences in these high-risk patients.

Left Atrial End-Diastolic Volume Index as a Predictor of Cardiovascular Outcomes: The Heart and Soul Study.

BACKGROUND: The left atrial end-systolic volume index (LAESVI) is a predictor of cardiovascular outcomes and is the recommended measurement of left atrial size. The left atrial end-diastolic volume index (LAEDVI), representing the minimum or residual left atrial volume, has not been fully evaluated as a predictor of cardiovascular events. This study evaluated the predictive power of LAEDVI compared with LAESVI for heart failure (HF) hospitalizations, a composite of HF hospitalizations, myocardial infarction, stroke, and heart disease death, and all-cause mortality. METHODS: We measured LAESVI and LAEDVI in subjects without atrial fibrillation or flutter or significant mitral valve disease. Using Cox proportional-hazard models, the association of LAESVI and LAEDVI with the stated outcomes was examined. RESULTS: After a mean of 7.3±2.6 years of follow-up, there were 147 HF hospitalizations, 118 myocardial infarctions, 45 strokes, 96 heart disease deaths, and 351 deaths from all causes in 938 subjects. When comparing the highest and the lowest quartiles of LAEDVI, there was a near 6-fold increase in the hazard ratio (HR) for HF hospitalization (HR, 5.96; P<0.001). This was higher than what was seen with LAESVI (HR, 4.85; P<0.001). Similar associations were noted for the composite cardiovascular outcome (HR for LAEDVI, 2.97; P<0.001) and for all-cause mortality (HR for LAEDVI, 2.08; P<0.001). In adjusted models, LAEDVI demonstrated equal or better predictive power than LAESVI for HF hospitalization and the composite cardiovascular outcome. CONCLUSIONS: LAEDVI is a strong predictor of cardiovascular events in ambulatory patients with stable coronary heart disease and may merit routine use.

Comparing Major Bleeding Risk in Outpatients With Atrial Fibrillation or Flutter by Oral Anticoagulant Type (from the National Cardiovascular Disease Registry's Practice Innovation and Clinical Excellence Registry).

Direct oral anticoagulants (DOACs) have a favorable bleeding risk profile in patients with atrial fibrillation (AF). However, the safety of individual DOACs relative to warfarin for specific bleeding outcomes is less certain. We identified 423,450 patients with AF between 2013 to 2015 in the NCDR PINNACLE national ambulatory registry matched to the Centers for Medicare and Medicaid Services database. Outcomes included time to first major bleed, intracranial hemorrhage (ICH), major gastrointestinal bleed (GIB), or other major bleed. We estimated the association of OAC with bleeding using Cox proportional hazard models. The median duration of follow-up was 1.4 years. OACs were used in 64% of AF patients (66% warfarin, 15% rivaroxaban, 12% dabigatran, and 7% apixaban). A major bleeding event occurred in 6.9% of patients. Compared with warfarin users, fewer patients experienced ICH with the use of rivaroxaban (HR 0.73; 95% CI 0.64 to 0.84), dabigatran (HR 0.56; 95% CI 0.48 to 0.65), and apixaban (HR 0.70; 95% CI 0.55 to 0.90). The risk of major GIB was higher in rivaroxaban users (HR 1.20; 95% CI 1.12 to 1.27), and lower in dabigatran (HR 0.88; 95% CI 0.82 to 0.95) and apixaban (HR 0.84; 95% CI 0.74 to 0.95) users. For any DOAC versus warfarin, age (≥75 or <75 years) interacted with major bleeding (HR 0.93 vs 0.78; p <0.001), GIB (HR 1.10 vs 0.82; p <0.001), and other major bleeding (HR 0.93 vs 0.80; p <0.001). In conclusion, our results suggest that the safety of DOACs is superior to warfarin in AF patients, except with rivaroxaban and GIB. Age ≥75 years attenuated the relative safety benefits of DOACs.

Attribution of Adverse Events Following Coronary Stent Placement Identified Using Administrative Claims Data.

Background More than 600 000 coronary stents are implanted during percutaneous coronary interventions (PCIs) annually in the United States. Because no real-world surveillance system exists to monitor their long-term safety, claims data are often used for this purpose. The extent to which adverse events identified with claims data can be reasonably attributed to a specific medical device is uncertain. Methods and Results We used deterministic matching to link the NCDR (National Cardiovascular Data Registry) CathPCI Registry to Medicare fee-for-service claims for patients aged ≥65 years who underwent PCI with drug-eluting stents (DESs) between July 1, 2009 and December 31, 2013. We identified subsequent PCIs within 1 year of the index procedure in Medicare claims as potential safety events. We linked these subsequent PCIs back to the NCDR CathPCI Registry to ascertain how often the revascularization could be reasonably attributed to the same coronary artery as the index PCI (ie, target vessel revascularization). Of 415 306 DES placements in 368 194 patients, 33 174 repeat PCIs were identified in Medicare claims within 1 year. Of these, 28 632 (86.3%) could be linked back to the NCDR CathPCI Registry; 16 942 (51.1% of repeat PCIs) were target vessel revascularizations. Of these, 8544 (50.4%) were within a previously placed DES: 7652 for in-stent restenosis and 1341 for stent thrombosis. Of 16 176 patients with a claim for acute myocardial infarction in the follow-up period, 4446 (27.5%) were attributed to the same coronary artery in which the DES was implanted during the index PCI (ie, target vessel myocardial infarction). Of 24 288 patients whose death was identified in claims data, 278 (1.1%) were attributed to the same coronary artery in which the DES was implanted during the index PCI. Conclusions Most repeat PCIs following DES stent implantation identified in longitudinal claims data could be linked to real-world registry data, but only half could be reasonably attributed to the same coronary artery as the index procedure. Attribution among those with acute myocardial infarction or who died was even less frequent. Safety signals identified using claims data alone will require more in-depth examination to accurately assess stent safety.

Incidence, duration, pattern, and burden of de novo atrial arrhythmias detected by continuous ECG monitoring using an implantable loop recorder following ablation of the cavotricuspid isthmus.

Background: Following cavotricuspid isthmus (CTI) ablation, many patients with atrial flutter (AFL) are diagnosed with atrial fibrillation (AF). The incidence, duration, pattern, and burden of AF remain undefined. These may have implications for the management of these patients. Objective: To classify the incidence, duration, pattern, and burden of AF/AFL using an implantable loop recorder (ILR) after CTI ablation. Methods: We enrolled consecutive patients with CTI-dependent AFL, no known history of AF, and CHA2DS2-VASc ≥ 2. An ILR was implanted before or within 90 days of ablation. The time to first AF/AFL, pattern, duration, and burden of longest AF/AFL were determined. Five distinct AF/AFL cohorts were identified: no AF/AFL and those with recurrences of isolated, clustered, frequent, or persistent AF/AFL. Results: Fifty-two patients (81% male; 73 ± 9 years; CHA2DS2-VASc 3.7 ± 1.2) were followed for 784 (interquartile range [IQR] 263, 1150) days. AF/AFL occurred in 44 (85%) patients at 64 (IQR 8, 189) days post-CTI ablation and was paroxysmal in 31 (70%) patients (burden 0.6% [IQR 0.1, 4.8]). AF/AFL was isolated (n = 5, 11%), clustered (n =7, 16%), frequent (n =19, 43%), and persistent (n =13, 30%). The longest AF episode was <24 hours in 27 (61%) patients. Conclusion: Following CTI ablation in AFL patients, although AF/AFL occurs in most patients, the burden is low and episodes were <24 hours in the majority of patients. Additional studies are needed to determine whether long-term electrocardiographic monitoring can help guide management of patients undergoing CTI ablation.

Detection of atrial fibrillation using an implantable loop recorder following cryptogenic stroke: implications for post-stroke electrocardiographic monitoring.

PURPOSE: Approximately 10-40% of strokes are cryptogenic (CS). Long-term electrocardiographic (ECG) monitoring has been recommended in these patients to search for atrial fibrillation (AF). An unresolved issue is whether ambulatory ECG (AECG) monitoring should be performed first, followed by an implantable loop recorder (ILR) if AECG monitoring is non-diagnostic, or whether long-term ECG monitoring should be initiated using ILRs from the onset. The purpose of this study was to assess, using an ILR, AF incidence in the first month after CS. METHODS: We enrolled consecutive CS patients referred for an ILR. All patients were monitored via in-hospital continuous telemetry from admission until the ILR (Medtronic [Minneapolis, MN] LINQ™) was implanted. The duration and overall burden of all AF episodes ≥ 2 min was determined. RESULTS: The cohort included 343 patients (68 ± 11 years, CHA2DS2-VASc 3.5 ± 1.7). The time between stroke and ILR was 3.7 ± 1.5 days. During the first 30 days, only 18 (5%) patients had AF. All episodes were paroxysmal, lasting from 2 min to 67 h and 24 min. The median AF burden was 0.85% (IQR 0.52, 10.75). During 1 year of follow-up, 67 (21%) patients had AF. CONCLUSION: The likelihood of AF detection by an ILR in the first month post-CS is low. Thus, the diagnostic yield of 30 days of AECG monitoring is likely to be limited. These data suggest a rationale for proceeding directly to ILR implantation prior to hospital discharge in CS patients, as many have AF detected during longer follow-up.

Who is young at heart and when? Diastolic Doppler data from the mind your heart study.

To further define the age-related distribution of diastolic function as defined by E/A ratio, in healthy male adults. The age-sensitive ratio of mitral inflow E-wave to A-wave (E/A) velocity is often considered in the evaluation of diastolic function. To appropriately direct a comprehensive evaluation of diastolic function, we sought to improve the characterization of the influence of age on E/A ratio. We analyzed echocardiographic data from the Mind Your heart Study, a cohort of outpatients recruited from two San Francisco Veterans centers to examine the effect of mental health on cardiovascular outcomes. Individuals with a history of heart disease or hypertension were excluded, leaving 313 veterans for analysis. We examined E/A by 5-year increments and performed linear and logistic regression analysis to predict trends in E/A and E dominance. Within the age ranges of population (54.9 ± 11.5), there is a steady gradual decline in absolute E/A ratio (beta coefficient/year- 0.018, P < .001) and the odds of E dominance similarly declines with age (odds ratio/year = 0.89, P < .001). Despite this decline, 90% of individuals below the age of 50 years maintain E dominance. Beyond age 50, 55% maintain E dominance, and beyond age 70, only 28% have E dominance. In this adequately healthy population, age-related progression of delayed relaxation appears to be a state of normality rather than diastolic dysfunction. Careful attention to specific cutoff points in age and E/A ratio could avoid misinterpretation or inappropriate management.

Comparison of Machine Learning Methods With National Cardiovascular Data Registry Models for Prediction of Risk of Bleeding After Percutaneous Coronary Intervention.

Importance: Better prediction of major bleeding after percutaneous coronary intervention (PCI) may improve clinical decisions aimed to reduce bleeding risk. Machine learning techniques, bolstered by better selection of variables, hold promise for enhancing prediction. Objective: To determine whether machine learning techniques better predict post-PCI major bleeding compared with the existing National Cardiovascular Data Registry (NCDR) models. Design, Setting, and Participants: This comparative effectiveness study used the NCDR CathPCI Registry data version 4.4 (July 1, 2009, to April 1, 2015), machine learning techniques were used (logistic regression with lasso regularization and gradient descent boosting [XGBoost, version 0.71.2]), and output was then compared with the existing simplified risk score and full NCDR models. The existing models were recreated, and then performance was evaluated through additional techniques and variables in a 5-fold cross-validation in analysis conducted from October 1, 2015, to October 27, 2017. The setting was retrospective modeling of a nationwide clinical registry of PCI. Participants were all patients undergoing PCI. Percutaneous coronary intervention procedures were excluded if they were not the index PCI of admission, if the hospital site had missing outcomes measures, or if the patient underwent subsequent coronary artery bypass grafting. Exposures: Clinical variables available at admission and diagnostic coronary angiography data were used to determine the severity and complexity of presentation. Main Outcomes and Measures: The main outcome was in-hospital major bleeding within 72 hours after PCI. Results were evaluated by comparing C statistics, calibration, and decision threshold-based metrics, including the F score (harmonic mean of positive predictive value and sensitivity) and the false discovery rate. Results: The post-PCI major bleeding rate among 3 316 465 procedures (patients' median age, 65 years; interquartile range, 56-73 years; 68.1% male) was 4.5%. The existing full model achieved a mean C statistic of 0.78 (95% CI, 0.78-0.78). The use of XGBoost and full range of selected variables achieved a C statistic of 0.82 (95% CI, 0.82-0.82), with an F score of 0.31 (95% CI, 0.30-0.31). XGBoost correctly identified an additional 3.7% of cases identified as high risk who experienced a bleeding event and an overall improvement of 1.0% of cases identified as low risk who did not experience a bleeding event. The data-driven decision threshold helped improve the false discovery rate of the existing techniques. The existing simplified risk score model improved the false discovery rate from more than 90% to 78.7%. Modifying the model and the data decision threshold improved this rate from 78.7% to 73.4%. Conclusions and Relevance: Machine learning techniques improved the prediction of major bleeding after PCI. These techniques may help to better identify patients who would benefit most from strategies to reduce bleeding risk.

Drug-associated valvular heart diseases and serotonin-related pathways: a meta-analysis.

OBJECTIVE: Serotonergic appetite suppressants and ergot-derived dopamine agonists have been associated with drug-induced valvular heart disease. The purpose of this meta-analysis is to synthesise the current evidence of a link between several medications affecting sertonergic pathways and valvular heart disease. METHODS: PubMed was searched to identify studies evaluating an association between medications with serotonergic activity and cardiac valvular pathology. Case reports, uncontrolled studies and in vitro studies were excluded. Relevant studies were assessed for quality and potential bias; those of adequate quality were included in a quantitative synthesis. Sensitivity analyses were conducted, and potential publication bias was examined. RESULTS: There was a consistent, significant relationship between certain medications and heart valve disease, including serotonergic medications (OR 3.30, 95% CI 1.99 to 5.49) and dopaminergic medications (OR 2.56, 95% CI 1.68 to 3.91). Subanalyses, including analyses that limited exposure to a single medication or effects to a single heart valve were also consistently significant. Most studies were retrospective or observational in nature, with a higher risk of selection and presentation biases. There was significant heterogeneity and variability between studies, particularly when it came to dose and duration of exposure. CONCLUSIONS: There was a consistent, significant association between many medications that affect serotonergic pathways and valvular heart disease. Although many of these medications have been withdrawn from the market, some small studies suggest that recreational drug 3,4-methylenedioxy​methamphetamine and widely prescribed selective serotonin reuptake inhibitors may affect similar pathways.

Characteristics and outcomes of maternal cardiac arrest: A descriptive analysis of Get with the guidelines data.

BACKGROUND: Maternal mortality has risen in the United States in the twenty-first century, yet large cohort data of maternal cardiac arrest (MCA) are limited. OBJECTIVE: We sought to describe contemporary characteristics and outcomes of in-hospital MCA. METHODS: We queried the American Heart Association's Get with the Guidelines Resuscitation voluntary registry from 2000 to 2016 to identify cases of maternal cardiac arrest. All index cardiac arrests occurring in women aged 18-50 with a patient illness category designated as obstetric or location of arrest occurring in a delivery suite were included. Institutional review deemed that this research was exempt from ethical approval. RESULTS: A total of 462 index events met criteria for MCA, with a mean age of 31 ± 7 years and a racial distribution of: 49.4% White, 35.3% Black and 15.3% Other/Unknown. While 32% had no pre-existing conditions or physiologic disorders, respiratory insufficiency (36.1%) and hypotension/hypoperfusion (33.3%) were the most common antecedent conditions. In most cases, the first documented pulseless rhythm was non-shockable; pulseless electrical activity (50.8%) or asystole (25.6%). Only 11.7% presented with a shockable rhythm; ventricular fibrillation (6.5%) or pulseless ventricular tachycardia (5.2%) while the initial pulseless rhythm was unknown in 11.9% of cases. Return of spontaneous circulation occurred in 73.6% but 68 (14.7%) had more than one arrest. The rate of survival to discharge was 40.7% overall; 37.3% with non-shockable rhythms, 33% with shockable rhythms and 64.3% with unknown presenting rhythms. CONCLUSIONS: Maternal survival at hospital discharge in this cohort was less than 50%, lower than rates reported in other epidemiological datasets. More research is required in maternal resuscitation science and translational medicine to continue to improve outcomes and understand maternal mortality.

Quantifying the utilization of medical devices necessary to detect postmarket safety differences: A case study of implantable cardioverter defibrillators.

PURPOSE: To estimate medical device utilization needed to detect safety differences among implantable cardioverter defibrillators (ICDs) generator models and compare these estimates to utilization in practice. METHODS: We conducted repeated sample size estimates to calculate the medical device utilization needed, systematically varying device-specific safety event rate ratios and significance levels while maintaining 80% power, testing 3 average adverse event rates (3.9, 6.1, and 12.6 events per 100 person-years) estimated from the American College of Cardiology's 2006 to 2010 National Cardiovascular Data Registry of ICDs. We then compared with actual medical device utilization. RESULTS: At significance level 0.05 and 80% power, 34% or fewer ICD models accrued sufficient utilization in practice to detect safety differences for rate ratios <1.15 and an average event rate of 12.6 events per 100 person-years. For average event rates of 3.9 and 12.6 events per 100 person-years, 30% and 50% of ICD models, respectively, accrued sufficient utilization for a rate ratio of 1.25, whereas 52% and 67% for a rate ratio of 1.50. Because actual ICD utilization was not uniformly distributed across ICD models, the proportion of individuals receiving any ICD that accrued sufficient utilization in practice was 0% to 21%, 32% to 70%, and 67% to 84% for rate ratios of 1.05, 1.15, and 1.25, respectively, for the range of 3 average adverse event rates. CONCLUSIONS: Small safety differences among ICD generator models are unlikely to be detected through routine surveillance given current ICD utilization in practice, but large safety differences can be detected for most patients at anticipated average adverse event rates.

Implications of coronary artery bypass grafting and percutaneous coronary intervention on disease progression and the resulting changes to the physiology and pathology of the native coronary arteries.

Myocardial revascularization can be achieved through 2 different methods: coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Clinical trials comparing PCI and CABG generally use the composite end points of death, stroke, myocardial infarction and target vessel revascularization to determine superiority. Other effects of these interventions, including the preservation of normal coronary physiology, the response of the coronary tree to stressors and the response of the vessel wall to the revascularization intervention, are not routinely considered, but these may have significant implications for patients in the medium and long term. For PCI, relatively small differences in clinical outcomes have been reported between bare metal and drug-eluting stents, and the latter seems to have inconsistent and somewhat unpredictable effects on the vascular biology of the coronary arteries. In coronary bypass, the use of arterial conduits is associated with superior clinical outcomes, better long-term patency and the preservation of essentially normal coronary function after intervention. This review assembles the clinical, physiological, angiographic and pathological literature currently available and attempts to provide a more complete picture of the effects of CABG and PCI on coronary arteries.

Usefulness of Epicardial Area in the Short Axis to Identify Elevated Left Ventricular Mass in Men.

Left ventricular (LV) hypertrophy is strongly associated with increased cardiovascular morbidity and mortality. The 2-dimensional LV mass algorithms suffer from measurement variability that can lead to misclassification of patients with LV hypertrophy as normal, or vice versa. Among the 4 echocardiographic measurements required by the 2-dimensional LV mass algorithms, epicardial and endocardial area have the lowest interobserver variation and could be used to corroborate LV mass calculations. We sought cut-off values that are able to discriminate between elevated and normal LV mass based on endocardial or epicardial area alone. Using data from 664 men enrolled in the Mind Your Heart Study, we calculated the correlation of LV mass index with epicardial area and endocardial area. We then used receiver operator characteristic curves to identify epicardial and endocardial area cut-points that could discriminate subjects with normal LV mass and LV hypertrophy. LV mass index was more strongly correlated with epicardial area compared with endocardial area, r = 0.70 versus r = 0.27, respectively. Epicardial area had a significantly higher area under the receiver operator characteristic curve (p <0.001) compared with endocardial area, 0.90 (95% confidence interval 0.86 to 0.93) versus 0.63 (95% confidence interval 0.57 to 0.71). An epicardial area cut-point of ≥38.0 cm2 corresponded to a sensitivity of 95.0% and specificity of 54.4% for detecting LV hypertrophy. In conclusion, epicardial area showed promise as a method of rapid screening for LV hypertrophy and could be used to validate formal LV mass calculations.