Role of Microalbuminuria in Predicting Cardiovascular Mortality in Individuals With Subclinical Hypothyroidism.

PURPOSE: Studies suggest that subclinical hypothyroidism (SCH) is related to cardiovascular mortality (CVM). We explored the role of microalbuminuria (MIA) as a predictor of long-term CVM in population with and without SCH with normal kidney function. MATERIALS AND METHODS: We examined the National Health and Nutrition Education Survey - III database (n = 6,812). Individuals younger than 40 years, thyroid-stimulating hormone levels ≥20 and ≤0.35mIU/L, estimated glomerular filtration rate <60mL/minute/1.73m2 and urine albumin-to-creatinine ratio of >250mg/g in men and >355mg/g in women were excluded. SCH was defined as thyroid-stimulating hormone levels between 5 and 19.99mIU/L and serum T4 levels between 5 and 12µg/dL. MIA was defined as urine albumin-to-creatinine ratio of 17-250mg/g in men and 25-355mg/g in women. Patients were categorized into the following 4 groups: (1) no SCH or MIA, (2) MIA, but no SCH, (3) SCH, but no MIA and (4) both SCH and MIA. RESULTS: Prevalence of MIA in the subclinical hypothyroid cohort was 21% compared to 16.4% in those without SCH (P = 0.03). SCH was a significant independent predictor of MIA (n = 6,812), after adjusting for traditional risk factors (unadjusted odds ratio = 1.75; 95% CI: 1.24-2.48; P = 0.002 and adjusted odds ratio = 1.83; 95% CI: 1.2-2.79; P = 0.006). MIA was a significant independent predictor of long-term all-cause (adjusted hazard ratio = 1.7, 95% CI: 1.24-2.33) and CVM (adjusted hazard ratio = 1.72, 95% CI: 1.07-2.76) in subclinical hypothyroid individuals. CONCLUSIONS: In a cohort of subclinical hypothyroid individuals, the presence of MIA predicts increased risk of CVM as compared to nonmicroalbuminurics with SCH. Further randomized trials are needed to assess the benefits of treating microalbuminuric subclinical hypothyroid individuals and impact on CVM.

Impact of hospital and sociodemographic factors on utilization of drug-eluting stents in 2011-2012 Medicare cohort.

OBJECTIVE: Insurance status is a predictor of drug-eluting stent (DES) usage. Our study sought to determine the effect of hospital and sociodemographic characteristics on utilization of DES in nationwide inpatient discharges with uniform insurance (Medicare). METHODS: We linked data from the 2011 to 2012 Medicare discharges, 2011 Medicare hospital referral region (HRR) report (racial composition of each HRR), American Hospital Association (number of beds, rural/urban location, public/private status, and academic affiliation of hospitals), and American Community Survey 2011 (median income using zip code). We analyzed diagnosis-related group (DRG) codes 249 (bare metal stent without complications), 246, and 247 (DES with and without complications, respectively). Univariate and multivariable logistic regression was conducted to determine odds ratios (OR) for utilization of DES. RESULTS: There were 322,002 discharges with DRG codes 246 (54,279), 247 (209,365), and 249 (58,358) in our database. Higher odds of DES usage was observed in Hispanic dominant HRR(s) (OR: 1.37, 95% confidence interval [CI]: 1.33-1.42, P < 0.001) compared to Caucasian dominant HRR(s). DES utilization was similar in African-American and Caucasian dominant HRR (s). Higher odds of DES use was observed in median household income groups ≥$20,001 (OR: 1.07, 95% CI: 1.01-1.13, P - 0.03). Lower DES usage was observed in hospitals with higher total stent volume (quartile 4 vs. quartile 1: OR: 0.66, 95% CI: 0.63-0.69, P < 0.001) and for-profit hospitals (OR: 0.88, 95% CI: 0.85-0.92, P < 0.001). CONCLUSIONS: Our study findings suggest that there are significant differences in DES utilization in a national cohort of individuals with uniform insurance.

Impact of Area Deprivation Index on Coronary Stent Utilization in a Medicare Nationwide Cohort.

Area Deprivation Index (ADI) is a marker of neighborhood deprivation. This study investigates utilization of coronary bare-metal stent (BMS) and drug-eluting stent (DES) in Medicare patients across hospitals with varying ADI. Data were abstracted using Diagnosis-Related Group (DRG) codes 249 (BMS without major complications or comorbidities [MCC]), 246, and 247 (DES with and without MCC, respectively) from the 2011-2012 Medicare Provider Utilization and Payment Data Inpatient File, which was linked to American Hospital Association data (to determine bed size, location, ownership, teaching status), and ADI for each hospital zip code was obtained. Hospitals were divided into quintiles using ADI values: Quintile 1 (privileged) to Quintile 5 (deprived). Logistic regression was conducted to determine odds ratios (ORs) for DES utilization across ADI quintiles. There were 313,739 discharges with DRG codes 246 (52,839), 247 (203,928), and 249 (56,972). DES utilization was lower in the deprived quintile, irrespective of teaching status. It was lower in larger hospitals and hospitals with more annual stent discharges, urban locations and nongovernment not-for-profit institutes. Lower odds of DES utilization were found in Quintile 2 (OR-0.9, 95% confidence interval [CI] 0.87-0.93, P < 0.001), Quintile 3 (OR-0.89, 95% CI 0.86-0.92, P < 0.001), and Quintile 4 (OR-0.95, 95% CI 0.92-0.98, P = 0.001) versus Quintile 1 and there was no difference in utilization of DES in Quintile 5 (OR-1.01, 95% CI 0.98-1.04, P = 0.6) versus Quintile 1. Significant differences exist in DES utilization in a large, uniformly insured cohort based on neighborhood deprivation.

Major electrocardiographic abnormalities and 25-hydroxy vitamin D deficiency: insights from National Health and Nutrition Examination Survey-III.

BACKGROUND: We explored the relationship between major electrocardiogram (ECG) abnormalities (mECG) and 25-hydroxy (25-OH) vitamin D deficiency (VDD) and the effect of mECG abnormalities on all-cause and cardiovascular mortality in a healthy cohort with 25-OH vitamin D insufficiency and deficiency. HYPOTHESIS: Lower levels of serum 25-OH vitamin D are associated with increased prevalence of mECG on resting ECG. METHODS: We identified 5108 individuals from the National Health and Nutrition Examination Survey-III. mECG abnormalities included: major Q-QS wave abnormalities, ST depression/elevation, negative T waves, Wolff-Parkinson-White pattern, and ventricular conduction defect. Our cohort was divided into 3 groups based on 25-OH vitamin D levels: Group 1 (referent): > 40 ng/mL; group 2 (insufficient): ≥ 20.01 to ≤ 40 ng/mL; and group 3 (deficient): ≤ 20 ng/mL. Logistic regression and Cox proportional hazards regression models were built. RESULTS: The prevalence of major ECG abnormalities across 25-OH vitamin D sufficiency, insufficiency, and deficiency was .9%, 11%, and 13 %, respectively (P = 0.01). VDD was an independent predictor of mECG abnormalities after adjusting for traditional risk factors (continuous variable odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97-0.99, P = 0.007; categorical variable group 3 vs group 1 OR: 2.36, 95% CI: 1.1-5.12, P = 0.03). Baseline major ECG abnormalities were predictive of long-term all-cause (hazard ratio [HR]:1.52, 95% CI: 1.23-1.89), composite cardiovascular (HR: 1.7, 95% CI: 1.34-2.15), cardiovascular (HR: 1.64, 95% CI: 1.27-2.12), and ischemic heart disease mortality (HR: 1.98, 95% CI: 1.46-2.69) in individuals with 25-OH vitamin D levels ≤ 40 ng/mL. CONCLUSIONS: VDD is associated with increased prevalence of major ECG abnormalities. Well-structured trials are needed to assess progression/resolution of mECG abnormalities with vitamin D supplementation in deficient individuals.

Burden of arrhythmias in patients with Takotsubo cardiomyopathy (apical ballooning syndrome).

INTRODUCTION: The objective of our study was to assess the burden of arrhythmias, the gender differences in occurrence of arrhythmias and the impact of these arrhythmias on hospitalization outcomes in patients with Takotsubo Cardiomyopathy (TTC). METHODS: TTC and various arrhythmias were identified using appropriate ICD-9-CM codes from Nationwide Inpatient Sample (NIS) discharge records 2006-2010. Length of hospital stay (LOS), in-hospital mortality and total charges were used to assess the impact of the arrhythmias on TTC hospitalization. All analyses were performed using SASv9.2 (Cary Institute Inc., Cary, NC). RESULTS: A total of 16,450 patients were included in the study and 26% (n=4296) of patients had cardiac arrhythmias. Following arrhythmias were present in the descending order of frequency: atrial fibrillation (Afib) 6.9%, ventricular tachycardia (VT) 3.2%, atrial flutter (Afl) 1.9%, ventricular fibrillation and flutter 1%, paroxysmal supraventricular tachycardia (PSVT) 0.8%. Nearly two percent of the patients had sudden cardiac arrest (SCA). Males were more likely to have cardiac arrhythmias in general compared to females (OR: 1.5, 95% CI: 1.3-1.7, p-value 0.001). Occurrence of ventricular tachycardia (OR: 1.7, 95% CI: 1.3-2.2, p-value<0.001) and sudden cardiac arrest OR: 1.6, 95% CI: 1.1-2.2, p<0.001) were significantly higher in males. In contrast, Afib was significantly less in males compared to females (OR:0.8, 95% CI:0.6-0.9). Patients with arrhythmias had significantly longer length of stay, and increased cost of hospitalization and mortality. CONCLUSIONS: Arrhythmias are present in nearly one-quarter of patients with TTC and worsen the outcome. While TTC has been established as a disease mainly of females, life threatening arrhythmias like VT and SCA are more common in males.

In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.

BACKGROUND: Atrial fibrillation ablation has made tremendous progress with respect to innovation, efficacy, and safety. However, limited data exist regarding the burden and trends in adverse outcomes arising from this procedure. The aim of our study was to examine the frequency of adverse events attributable to atrial fibrillation (AF) ablation and the influence of operator and hospital volume on outcomes. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample, we identified AF patients treated with catheter ablation. We investigated common complications including cardiac perforation and tamponade, pneumothorax, stroke, transient ischemic attack, vascular access complications (hemorrhage/hematoma, vascular complications requiring surgical repair, and accidental arterial puncture), and in-hospital death described with AF ablation, and we defined these complications by using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. An estimated 93,801 AF ablations were performed from 2000 to 2010. The overall frequency of complications was 6.29% with combined cardiac complications (2.54%) being the most frequent. Cardiac complications were followed by vascular complications (1.53%), respiratory complications (1.3%), and neurological complications (1.02%). The in-hospital mortality was 0.46%. Annual operator (<25 procedures) and hospital volume (<50 procedures) were significantly associated with adverse outcomes. There was a small (nonsignificant) rise in overall complication rates. CONCLUSIONS: The overall complication rate was 6.29% in patients undergoing AF ablation. There was a significant association between operator and hospital volume and adverse outcomes. This suggests a need for future research into identifying the safety measures in AF ablations and instituting appropriate interventions to improve overall AF ablation outcomes.

Electrocardiographic abnormalities and reclassification of cardiovascular risk: insights from NHANES-III.

BACKGROUND: We aimed to assess the additive value of electrocardiogram (ECG) findings to risk prediction models for cardiovascular disease. METHODS: Our dataset consisted of 6025 individuals with ECG data available from the National Health and Nutrition Examination Survey-III. This is a self-weighting sample with a follow-up of 79,046.84 person-years. The primary outcomes were cardiovascular mortality and all-cause mortality. We compared 2 models: Framingham Risk Score (FRS) covariates (Model A) and ECG abnormalities added to Model A (Model B), and calculated the net reclassification improvement index (NRI). RESULTS: Mean age of our study population was 58.7 years; 45.6% were male and 91.7% were white. At baseline, 54.6% of individuals had ECG abnormalities, of which 545 (9%) died secondary to a cardiovascular event, compared with 194 individuals (3.2%) (P <.01) without ECG abnormalities. ECG abnormalities were significant predictors of cardiovascular mortality after adjusting for traditional cardiovascular risk factors (hazard ratio 1.44; 95% confidence interval, 1.13-1.83). Addition of ECG abnormalities led to an overall NRI of 3.6% subjects (P <.001) and 13.24% in the intermediate risk category. The absolute integrated discrimination index was 0.0001 (P <.001). CONCLUSION: Electrocardiographic abnormalities are independent predictors of cardiovascular mortality, and their addition to the FRS improves model discrimination and calibration. Further studies are needed to assess the prospective application of ECG abnormalities in cardiovascular risk prediction in individual subjects.

Combined use of direct renin inhibitor and carvedilol in heart failure with preserved systolic function.

HYPOTHESES: Heart failure with preserved systolic function (HFPSF) has attained epidemic proportions; however evidence-based therapeutic interventions have not advanced despite continued research over the past three decades. We propose the combined use of direct renin inhibitor and carvedilol for this condition. RATIONALE: The Renin Angiotensin Aldosterone System (RAAS) plays a central role in myocyte hypertrophy, fibrosis and ventricular remodeling which is responsible for the diastolic dysfunction in HFPSF. Rising serum aldosterone levels with age have been implicated as a cause of myocardial fibrosis in the elderly. The sole use of Angiotensin Converting Enzyme Inhibitors or Angiotensin Receptor Blockers is associated with angiotensin-II and aldosterone escape and increased plasma renin activity. Carvedilol is a novel third generation non-selective ß-blocker. The use of combination therapy will facilitate in better blood pressure control, reduce afterload, improve ventricular relaxation, cause regression of ventricular remodeling/fibrosis, maintain atrioventricular synchrony and enhance cardio-metabolic profile. The individual benefits of direct renin inhibitor and carvedilol could plausibly have a supra-additive effect when used in combination. Besides this, carvedilol can further reduce generation of free radicals, decrease LDL oxidation, improve Doppler echo diastolic parameters and decrease cardiac norepinephrine and density of cardiac ß-receptors. CONCLUSION: Evidence suggests that patients with HFPSF are treated less aggressively as compared to patients with heart failure with systolic dysfunction. Aggressive therapy with concurrent use of direct renin inhibitor and carvedilol will help in improving outcomes in this vulnerable patient sub-population. No prior trial has evaluated the combined use of these drugs for the treatment of HFPSF.

Atrial fibrillation post cardiac bypass surgery.

Atrial fibrillation occurs in 5-40% patients after coronary artery bypass graft surgery. Atrial fibrillation increases mortality and morbidity in the post-operative period. We sought to conduct a comprehensive review of literature focusing on pathophysiology, risk factors, prevention and treatment of post coronary artery bypass graft atrial fibrillation.