Prashant D. Bhave

Paroxysmal Supraventricular Tachycardia and the Risk of Ischemic Stroke

Background and Purpose— It is unknown whether supraventricular arrhythmias other than atrial fibrillation or flutter are associated with stroke. Methods— To examine the association between paroxysmal supraventricular tachycardia (PSVT) and stroke, we performed a retrospective cohort study using administrative claims data from all emergency department encounters and hospitalizations at California’s nonfederal acute care hospitals in 2009. Our cohort comprised all adult patients with ≥1 emergency department visit or hospitalization from which they were discharged alive and without a diagnosis of stroke. Our primary exposure was a diagnosis of PSVT recorded at an encounter before stroke or documented as present-on-admission at the time of stroke. To reduce confounding, we excluded patients with diagnoses of atrial fibrillation. We defined PSVT, stroke, and atrial fibrillation using International Classification of Diseases, Ninth Revision, Clinical Modification codes previously validated by detailed chart review. Results— Of 4 806 830 eligible patients, 14 121 (0.29%) were diagnosed with PSVT and 14 402 (0.30%) experienced a stroke. The cumulative rate of stroke after PSVT diagnosis (0.94%; 95% confidence interval, 0.76%–1.16%) significantly exceeded the rate among patients without a diagnosis of PSVT (0.21%; 95% confidence interval, 0.21%–0.22%). In Cox proportional hazards analysis controlling for demographic characteristics and potential confounders, PSVT was independently associated with a higher risk of subsequent stroke (hazard ratio, 2.10; 95% confidence interval, 1.69–2.62). Conclusions— In a large and demographically diverse sample of patients, we found an independent association between PSVT and ischemic stroke. PSVT seems to be a novel risk factor that may account for some proportion of strokes that are currently classified as cryptogenic.

Race- and sex-related differences in care for patients newly diagnosed with atrial fibrillation.

BACKGROUNDnAtrial fibrillation (AF) is associated with an increased risk of stroke and death. Uniform utilization of appropriate therapies for AF may help reduce those risks.nnnOBJECTIVEnWe sought to determine whether significant race and sex differences exist in the treatment of newly diagnosed AF in Medicare beneficiaries.nnnMETHODSnWe used administrative encounter data for Medicare beneficiaries to identify patients with newly diagnosed AF during 2010-2011. Services received after initial AF diagnosis were cataloged, including visits with a cardiologist or electrophysiologist, catheter ablation procedures, and use of oral anticoagulants, rate control agents, and antiarrhythmic drugs.nnnRESULTSnOverall, 517,941 patients met study criteria, of whom 452,986 (87%) were white, 36,425 (7%) black, and 28,530 (6%) Hispanic. Male patients comprised 209,788 (41%) of the cohort. In multivariate analysis, there were statistically significant differences in the use of AF-related services by both race and sex, with white patients and male patients receiving the most care. The most notable disparities were for catheter ablation (Hispanic vs white: adjusted hazard ratio [AHR] 0.70; 95% confidence interval [CI] 0.63-0.79; P < .001; female vs male: AHR 0.65; 95% CI 0.63-0.68; P < .001) and receipt of oral anticoagulation (black vs white: AHR 0.94; 95% CI 0.92-0.95; P < .001; Hispanic vs white: AHR 0.94; 95% CI 0.93-0.97; P < .001; female vs male: AHR 0.93; 95% CI 0.93-0.94; P < .001).nnnCONCLUSIONnRace and sex appear to have a significant effect on the health care provided to this cohort of Medicare beneficiaries diagnosed with AF. Possible explanations include racial differences in access, patient preferences, treatment bias, and unmeasured clinical characteristics.

Caffeine and atrial fibrillation: friends or foes?

Caffeine is a methylxanthine compound that has pleiotropic cardiovascular effects, including stimulation of the sympathetic nervous system. Caffeine is ingested daily by a large percentage of the global population (in the form of tea, coffee and cola), and is the most widely consumed vasoactive substance in the world.1nnThe relationship of caffeine to cardiovascular disease has been debated and investigated for decades. Considered a stimulant, caffeine had long been postulated to be proarrhythmic. Initial physiologic measurements in humans showed that acute caffeine ingestion in caffeine naive subjects increased heart rate and blood pressure, and correlated with increases in plasma renin and catecholamine levels.2 Electrophysiological studies performed in the 1980s during acute caffeine loading (both oral and intravenous) demonstrated a heterogeneous pattern of effect in cardiac tissue, with caffeine prolonging the myocardial refractory period in the left atrium and shortening the refractory period in the right atrium.3 In these experiments, patients seemed to have an increased proclivity to develop supraventricular arrhythmia after caffeine loading.nnThe results of these early studies suggested a deleterious effect of caffeine on cardiovascular health. Importantly, however, these studies investigated the acute effects of caffeine ingestion and not the chronic effects of daily exposure in a habituated subject. The keen interest in identifying potential ill effects of caffeine consumption led to high-profile publications, including one linking coffee drinking to pancreatic cancer—a finding later debunked, as it resulted from the use of flawed statistical and study design methods.4nnRecently, interest in identifying risk factors for supraventricular arrhythmias has increased—particularly with respect to atrial fibrillation (AF), given the high prevalence of this dysrhythmia and the risk of …

Sex-Specific Comparative Effectiveness of Oral Anticoagulants in Elderly Patients With Newly Diagnosed Atrial Fibrillation

Background— Sex-specific comparative effectiveness of direct oral anticoagulants among patients with nonvalvular atrial fibrillation is not known. Via this retrospective cohort study, we assessed the sex-specific, comparative effectiveness of direct oral anticoagulants (rivaroxaban and dabigatran), compared to each other and to warfarin among patients with atrial fibrillation. Methods and Results— Elderly (aged ≥66 years) Medicare beneficiaries enrolled in Medicare Part D benefit plan from November 2011 to October 2013 with newly diagnosed atrial fibrillation formed the study cohort (65 734 [44.8%] men and 81 137 [55.2%] women). Primary outcomes of inpatient admissions for ischemic strokes and major bleeding were compared across the 3 drugs (rivaroxaban: 20 mg QD, dabigatran: 150 mg BID, or warfarin) using 3-way propensity-matched samples. In men, rivaroxaban use decreased stroke risk when compared with warfarin use (hazard ratio, 0.69; 95% confidence interval, 0.48–0.99; P=0.048) and dabigatran use (hazard ratio, 0.66; 95% confidence interval, 0.45–0.96; P=0.029) and was associated with a similar risk of any major bleeding when compared with warfarin and dabigatran. In women, although ischemic stroke risk was similar in the 3 anticoagulant groups, rivaroxaban use significantly increased the risk for any major bleeding when compared with warfarin (hazard ratio, 1.20; 95% confidence interval, 1.03–1.42; P=0.021) and dabigatran (hazard ratio, 1.27; 95% confidence interval, 1.09–1.48; P=0.011). Conclusions— The reduced risk of ischemic stroke in patients taking rivaroxaban, compared with dabigatran and warfarin, seems to be limited to men, whereas the higher risk of bleeding seems to be limited to women.

Predictors of Unusual ECG Characteristics in Cavotricuspid Isthmus-Dependent Atrial Flutter Ablation

Background: u2002An unusual 12‐lead electrocardiographic pattern may be present in patients with cavotricuspid isthmus (CTI)‐dependent flutter.

An Unusual Pattern of ST-Segment Elevation

-amine-induced dilated cardiomyopathywas referred from clinic to the emer-gency department after having had anepisode of chest pain during his clinicvisit. The patient reported exertional chest discomfort,described as a pressurelike sensation accompanied bysweating.Thediscomfortresolvedwithrestandsublin-gual nitroglycerin. He admitted to recent methamphet-amine use. His blood pressure was 136/70 mm Hg, andhis heart rate was regular at 99 beats/min. The jugularvenous pressure was mildly elevated, and an S3 gallopwas audible at the apex. His initial troponin-I level was0.10 ng/mL (normal !0.10 ng/mL). An electrocardio-gram (ECG) showed normal sinus rhythm and left ven-tricular hypertrophy with associated repolarizationabnormalities.Thepatientwasadmittedtothehospitalforserialcar-diacenzymedeterminations.Onthesecondhospitalday,the patient suddenly became profusely diaphoretic andcomplained of chest pain. An ECG was obtained(

Sex‐Specific Associations of Oral Anticoagulant Use and Cardiovascular Outcomes in Patients With Atrial Fibrillation

Background Sex‐specific effectiveness of rivaroxaban (RIVA), dabigatran (DABI), and warfarin in reducing myocardial infarction (MI), heart failure (HF), and all‐cause mortality among patients with atrial fibrillation are not known. We assessed sex‐specific associations of RIVA, DABI, or warfarin use with the risk of MI, HF, and all‐cause mortality among patients with atrial fibrillation. Methods and Results Medicare beneficiaries (men: 65 734 [44.8%], women: 81 135 [55.2%]) with atrial fibrillation who initiated oral anticoagulants formed the study cohort. Inpatient admissions for MI, HF, and all‐cause mortality were compared between the 3 drugs separately for men and women using 3‐way propensity‐matched samples. In men, RIVA use was associated with a reduced risk of MI admissions compared with warfarin use (hazard ratio [95% confidence interval (CI): 0.59 [0.38–0.91]), with a trend towards reduced risk compared with DABI use (0.67 [0.44–1.01]). In women, there were no significant differences in the risk of MI admissions across all 3 anticoagulants. In both sexes, RIVA use and DABI use were associated with reduced risk of HF admissions (men: RIVA; 0.75 [0.63–0.89], DABI; 0.81 [0.69–0.96]) (women: RIVA; 0.64 [0.56–0.74], DABI; 0.73 [0.63–0.83]) and all‐cause mortality (men: RIVA; 0.66 [0.53–0.81], DABI; 0.75 [0.61–0.93]) (women: RIVA; 0.76 [0.63–0.91], DABI; 0.77 [0.64–0.93]) compared with warfarin use. Conclusions RIVA use and DABI use when compared with warfarin use was associated with a reduced risk of HF admissions and all‐cause mortality in both sexes. However, reduced risk of MI admissions noted with RIVA use appears to be limited to men.

Gender Differences in the Trends of Hospitalizations for Acute Stroke Among Patients With Atrial Fibrillation in the United States: 2005 to 2014

Female gender was included in stroke prediction algorithms in an attempt to improve anticoagulation rates in women with atrial fibrillation (AF). It is unclear if these efforts reduced stroke burden in women with AF. To bridge this literature gap, using the Nationwide Inpatient Sample, we assessed gender differences in the trends of hospitalizations for stroke among patients with AF in the United States in 2005 to 2014. International classification of diseases, 9th revision, clinical modification codes were used to abstract AF and stroke diagnoses. From 2005 to 2014, 18,413,291 hospitalizations of women with AF and 18,035,866 hospitalizations of men with AF were reported. Of these, 740,635 hospitalizations in women and 595,730 hospitalizations in men had stroke as the primary diagnosis. Age-adjusted stroke hospitalizations increased in women (443 per million in 2005 to 495 per million in 2014) as well as in men (351 per million in 2005 to 453 per million in 2014) (p trendu2009<u20090.001). Further, anticoagulation rates increased in women (11.5% in 2005 to 24.0% in 2014) as well as in men (11.7% in 2005 to 24.9% in 2014). Stroke hospitalizations involving anticoagulated patients with AF decreased in women (411 per million in 2005 to 347 per million in 2014) as well as in men (402 per million in 2005 to 311 per million in 2014) (p trendu2009<u20090.001). In conclusion, although we noted an increasing trend of stroke hospitalizations in both genders, it is reassuring to note that stroke hospitalizations involving anticoagulated patients with AF is decreasing in both genders and in particular among women.

What do our patients think they know about atrial fibrillation? … Is that asking the right question?

Inxa0theirxa0 Heart xa0publication, Kaufman et al 1 analysedxa0survey data examining patients’ self-reported understanding of various elements of care regarding their atrial fibrillation (AF). The authors used a cohort of patients recently diagnosed with AF from a substudy of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillationxa0(ORBIT) II registry. The authors found that on initial survey, about half of patients reported a high understanding of various elements of AF care, such as the benefits of taking blood thinner. Exceptions included ‘role of rhythm control’ (for which 70% of patients reported a high understanding) and ‘benefits of left atrial appendage closure’ (for which only 8% of patients reported a high understanding). Overall, patient self-report of understanding of various AF treatment modalities did improve somewhat between baseline and 6-month follow-up; however, there was also some regression—for instance, 15%–20% of patients who reported high understanding of the benefits of oral anticoagulation at baseline reported a downgrade in that level of understanding 6 months later. With the exception of catheter ablation, patients self-perceived understanding of a given modality of AF care did not correlate to the frequency of use of that modality in their care.nnThis manuscript raises a number of important issues that are pertinent to the way that we care for patients with any chronic disease, not just AF. …

Role of obstructive sleep apnea on the response to cardiac resynchronization therapy and all-cause mortality

BACKGROUNDnThe role of obstructive sleep apnea (OSA) on the response to cardiac resynchronization therapy (CRT) and all-cause mortality in patients with advanced heart failure (HF) is unknown.nnnOBJECTIVEnWe assessed the association between OSA, response to CRT, and all-cause mortality in patients with HF.nnnMETHODSnWe analyzed records of 548 consecutive patients (mean age 65 ± 13 years; 216 (39%) women; mean follow-up period 76 ± 17 months) who received a CRT-defibrillator device from January 15, 2007 to March 30, 2016 at our tertiary care referral center.nnnRESULTSnA total of 180 patients (33%) had OSA. Fewer patients in the OSA group (109 [61%]) had improvement in left ventricular ejection fraction (EF) than did those in the non-OSA group (253 [69%]) (P = .001). A total of 144 patients (27%) died by the end of follow-up (OSA group: 61 [33%]; non-OSA group 83 [23%]; P < .001). OSA diagnosis was associated with a lower chance of improvement in EF (hazard ratio 0.71; 95% confidence interval 0.60-0.89) and a higher risk of all-cause mortality (hazard ratio 3.7; 95% confidence interval 2.5-6.8). This was true in continuous positive airway pressure-compliant patients and in patients with nonischemic cardiomyopathy. However, among patients with ischemic cardiomyopathy, the chance of improvement in EF and all-cause mortality was similar in patients with OSA and those without OSA.nnnCONCLUSIONnOSA is associated with a decreased response to CRT and an increase in all-cause mortality in patients with HF. The differential effect of OSA on CRT response in patients with ischemic cardiomyopathy and nonischemic cardiomyopathy needs further study.