Contemporary trends of hospitalization for atrial fibrillation in the United States, 2000 through 2010: implications for healthcare planning.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The associated morbidity and mortality make AF a major public health burden. Hospitalizations account for the majority of the economic cost burden associated with AF. The main objective of this study is to examine the trends of AF-related hospitalizations in the United States and to compare patient characteristics, outcomes, and comorbid diagnoses. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample from 2000 through 2010, we identified AF-related hospitalizations using International Classification of Diseases, 9th Revision, Clinical Modification code 427.31 as the principal discharge diagnosis. Overall AF hospitalizations increased by 23% from 2000 to 2010, particularly in patients ≥65 years of age. The most frequent coexisting conditions were hypertension (60.0%), diabetes mellitus (21.5%), and chronic pulmonary disease (20.0%). Overall in-hospital mortality was 1%. The mortality rate was highest in the group of patients ≥80 years of age (1.9%) and in the group of patients with concomitant heart failure (8.2%). In-hospital mortality rate decreased significantly from 1.2% in 2000 to 0.9% in 2010 (29.2% decrease; P<0.001). Although there was no significant change in mean length of stay, mean cost of AF hospitalization increased significantly from $6410 in 2001 to $8439 in 2010 (24.0% increase; P<0.001). CONCLUSIONS: Hospitalization rates for AF have increased exponentially among US adults from 2000 to 2010. The proportion of comorbid chronic diseases has also increased significantly. The last decade has witnessed an overall decline in hospital mortality; however, the hospitalization cost has significantly increased.

Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009).

BACKGROUND: The relationship between operator or institutional volume and outcomes among patients undergoing percutaneous coronary interventions (PCI) is unclear. METHODS AND RESULTS: Cross-sectional study based on the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample between 2005 to 2009. Subjects were identified by International Classification of Diseases, 9(th) Revision, Clinical Modification procedure code, 36.06 and 36.07. Annual operator and institutional volumes were calculated using unique identification numbers and then divided into quartiles. Three-level hierarchical multivariate mixed models were created. The primary outcome was in-hospital mortality; secondary outcome was a composite of in-hospital mortality and peri-procedural complications. A total of 457,498 PCIs were identified representing a total of 2,243,209 PCIs performed in the United States during the study period. In-hospital, all-cause mortality was 1.08%, and the overall complication rate was 7.10%. The primary and secondary outcomes of procedures performed by operators in 4(th) [annual procedural volume; primary and secondary outcomes] [>100; 0.59% and 5.51%], 3(rd) [45-100; 0.87% and 6.40%], and 2(nd) quartile [16-44; 1.15% and 7.75%] were significantly less (P<0.001) when compared with those by operators in the 1(st) quartile [≤15; 1.68% and 10.91%]. Spline analysis also showed significant operator and institutional volume outcome relationship. Similarly operators in the higher quartiles witnessed a significant reduction in length of hospital stay and cost of hospitalization (P<0.001). CONCLUSIONS: Overall in-hospital mortality after PCI was low. An increase in operator and institutional volume of PCI was found to be associated with a decrease in adverse outcomes, length of hospital stay, and cost of hospitalization.

Influence of hospital volume on outcomes of percutaneous atrial septal defect and patent foramen ovale closure: a 10-years US perspective.

BACKGROUND: Contemporary data regarding percutaneous closure of atrial septal defect/patent foramen ovale (ASD/PFO) are lacking. We evaluated the current trends in utilization of ASD/PFO closure in adults and investigated the effect of annual hospital volume on in-hospital outcomes. METHODS: We queried the Nationwide Inpatient Sample between the years 2001 and 2010 using the International Classification of Diseases (ICD-9-CM) procedure code for percutaneous closure of ASD/PFO with device. Hierarchical mixed effects models were generated to identify the independent multivariate predictors of outcomes. RESULTS: A total of 7,107 percutaneous ASD/PFO closure procedures (weighted n = 34,992) were available for analysis. A 4.7-fold increase in the utilization of this procedure from 3/million in 2001 to 14/million adults in 2010 in US (P < 0.001) was noted. Overall, percutaneous ASD/PFO closure was associated with 0.5% mortality and 12% in-hospital complications. The utilization of intracardiac echocardiography (ICE) increased 15 fold (P < 0.001) during the study period. The procedures performed at the high volume hospitals [2nd (14-37 procedures/year) and 3rd (>38 procedures/year) tertile] were associated with significant reduction in complications, length of stay and cost of hospitalization when compared to those performed at lowest volume centers (<13 procedures/year). Majority (70.5%) of the studied hospitals were found to be performing <10 procedures/year hence deviating from the ACC/AHA/SCAI clinical competency guidelines. CONCLUSIONS: Low hospital volume is associated with an increased composite (mortality and procedural complications) adverse outcome following ASD/PFO closure. In the interest of patient safety, implementation of the current guidelines for minimum required annual hospital volume to improve clinical outcomes is warranted.

Three-dimensional echocardiographic assessment of patent foramen ovale in platypnea-orthodeoxia.

Platypnea-orthodeoxia is an uncommon syndrome characterized by positional dyspnea and hypoxia when upright that improves with lying down. We present a 75-year-old man with platypnea-orthodeoxia in the setting of a patent foramen ovale (PFO) and a 2.1 cm highly mobile atrial septal aneurysm with 2 cm bowing. Prior reports have established the use of three-dimensional echocardiography to facilitate percutaneous closure of PFO and atrial septal defect, but its use in patients with platypnea-orthodeoxia is unclear. We document three-dimensional echocardiographic images that accurately estimated PFO defect size and confirmed placement of the occluder device.

Statin therapy significantly reduces risk of ventricular tachyarrhythmias in patients with an implantable cardioverter defibrillator.

A few observational studies have shown the protective effect of statins on preventing ventricular tachycardia/ventricular fibrillation (VT/VF). However, the disparate study results prompt further exploration of this concept. We performed a meta-analysis to assess whether statin therapy is associated with a decrease in the incidence or recurrence of VT/VF in patients with an implantable cardioverter-defibrillator (ICD).The MEDLINE(®) and Cochrane databases were searched from 1980 to July 2009 for studies examining the effect of statins on VT/VF in recipients of ICDs. We retrieved all prospective cohort studies that examined this association. The endpoint was defined as appropriate ICD therapy for VT/VF. The quality of individual studies was assessed using the Newcastle Ottawa Scale.Seven prospective cohort studies met our inclusion criteria with a total of 2278 patients with a mean follow-up of 19.7 months. Pooled analysis of the eligible studies revealed that statin therapy was associated with a 45% reduction in the risk of developing VT/VF in recepients of ICDs [pooled odds ratio (pOR): 0.55; 95% confidence interval: 0.34-0.90; heterogeneity I(2) = 81%, P = 0.02]. In a subgroup analysis, the magnitude of the risk reduction in patients with ischemic cardiomyopathy was 54% (pOR: 0.46, P = 0.05). Sensitivity analysis including studies with higher methodological qualities alone showed a significant protective effect (pOR: 0.48, P = 0.01). There was no evidence of publication bias in the analysis.Our meta-analysis suggests an association between the use of statin and a reduction in the VT/VF occurrence in recipients of ICDs, mainly in patients with ischemic cardiomyopathy.

Preserved or slightly depressed ejection fraction and outcomes after myocardial infarction.

BACKGROUND Left ventricular ejection fraction (EF) in post-myocardial infarction (MI) patients is a strong predictor of adverse cardiovascular events. Although resting EF as measured by transthoracic echocardiography (TTE), contrast ventriculography (CNV), and radionuclide angiography (RNA) exhibit high correlation, there is only modest agreement between these modalities. This study sought to explore whether modality of EF assessment influences prognostication of post-MI patients with normal or slightly reduced EF. METHODS AND RESULTS The National Heart, Lung, and Blood Institute (NHLBI) limited access dataset of the Prevention of Events with Angiotensin Converting Enzyme Inhibition (PEACE) Trial (1996-2003, n=8290) comparing trandolapril versus placebo was used. The cohort was partitioned into TTE (n=2582), RNA (n=816), and CNV (n=1155) groups based on modality of EF assessment. EF was a significant predictor of cardiovascular mortality (HR 0.97, 95% CI 0.95 to 0.98; p<0.005) and all cause mortality (HR 0.98, 95% CI 0.97 to 0.99; p=0.0002) on multivariate analysis in this population with preserved or mildly depressed EF. Although CNV, TTE, and RNA groups differed significantly in terms of baseline variables, no appreciable differences were noted between RNA (HR 1.13, 95% CI 0.85 to 1.50; ns) and CNV (HR 1.13, 95% CI 0.99 to 1.27; ns) groups, compared with TTE for all cause mortality. Similarly, no significant differences were observed for cardiovascular mortality between RNA (HR 1.23, 95% CI 0.82 to 1.84; p=0.31) and CNV (HR 1.14, 95% CI 0.78 to 1.67, p=0.49) versus TTE. CONCLUSION EF is a significant predictor of all-cause mortality and cardiovascular mortality in patients with preserved or mildly depressed EF. Modalities of EF measurement are interchangeable and do not play a significant role in prognostication in a post-MI population.

Is positron emission tomography enough to rule out cardiac sarcoidosis? A case report.

BACKGROUND: Cardiac sarcoidosis (CS) is associated with poor prognosis, yet the clinical diagnosis is often challenging. Advanced cardiac imaging including cardiac magnetic resonance (CMR) and positron emission tomographic (PET) have emerged as useful modalities to diagnose CS. CASE SUMMARY: A 66-year-old woman presented with palpitations. A 24-h Holter monitor detected a high premature ventricular contraction burden of 25.6%. She underwent two transthoracic echocardiograms; both showed normal results. Stress perfusion CMR did not show any evidence of ischaemic aetiology; however, myocardial lesions detected by late gadolinium enhancement (LGE) imaging raised suspicion for CS. While there was no myocardial uptake of fluorodeoxyglucose (FDG) in subsequent cardiac PET, high FDG uptake was seen in hilar lymph nodes. Lymph node biopsy confirmed the diagnosis of sarcoidosis. DISCUSSION: Cardiac magnetic resonance and PET imaging are designed to evaluate different aspects CS pathophysiology. The characteristic LGE in the absence of increased FDG uptake suggested inactive CS with residual myocardial scarring.

Supracristal Ventricular Septal Defect Complicated by Formation of an Aorto-Right Ventricular Outflow Tract Fistula: A Rare Cause of Biventricular Enlargement.

Aorto-right ventricular outflow tract fistulas typically occur secondary to trauma, infective endocarditis, and sinus of Valsalva aneurysm rupture. We describe an unusual case of a spontaneous aorto-right ventricular outflow tract fistula in the absence of such findings, instead forming secondary to a complicating supracristal ventricular septal defect and leading to dilated cardiomyopathy.

Recurrent ventricular tachycardia associated with lipomatous metaplasia of a myocardial scar.

Lipomatous metaplasia in chronic postmyocardial infarction scars is a common and underappreciated finding seen in histopathology and cardiac MRI. Evidence suggests that lipomatous metaplasia is capable of altering the electroconductivity of the myocardium leading to re-entry pathways that are implicated in the pathogenesis of postmyocardial infarction arrhythmogenesis. We report a case of a patient who presented with non-sustained ventricular tachycardia and was found to have lipomatous metaplasia of a prior myocardial infarct-related scar.

Renal disease and cardiac mortality in survivors of sudden cardiac death.

OBJECTIVE: Renal disease is associated with increased all-cause mortality and cardiovascular mortality. However, the role of ICD implantation on cardiac mortality in patients with renal disease has not been well studied. Implantable cardioverter-defibrillator (ICD) implantation is protective against cardiac death in a secondary prevention population with renal disease. METHODS: The Antiarrhythmics Versus Implantable Cardioverter Defibrillators (AVID) Trial (n = 1016) was a multicentre trial comparing ICD (n = 507) and anti-arrhythmic drugs (AAD) (n = 509) for secondary prevention of life-threatening ventricular tachyarrhythmias. We performed a post-hoc analysis of the AVID trial using the National Heart, Lung, and Blood Institute limited access dataset. Individuals in the original AVID study with history of renal disease (n = 82) were included in this analysis. Outcomes of our analysis were cardiac death and all-cause mortality. RESULTS: 41 patients had renal disease in both the ICD and AAD arms. A total of 116 patients died in the ICD arm, while 162 died in the AAD arm. Renal disease was an independent predictor (HR, 95% CI) of cardiac death (1.967, 1.09-3.57, P = 0.02) and all-cause mortality (2.04, 1.23-3.39, P = 0.01) in the AAD arm. Renal disease was also a predictor of all-cause mortality in the ICD arm (1.75, 1.01-3.01, P = 0.04). However, renal disease did not influence cardiac death in the ICD arm. CONCLUSIONS: Our study investigates the effect of ICD implantation in an entirely secondary prevention population with renal disease. ICD implantation appears to be equally protective against cardiac death in renal disease when compared to AAD.

Unusual presentation of left ventricular rupture.

We describe a case of 49-year-old man who presented with chest pain and was diagnosed with non-ST elevation myocardial infarction. Transthoracic echocardiogram (TTE) showed severe global hypokinesis of left ventricle with ejection fraction of 25%-30%. Left heart catheterisation showed severe right coronary stenosis and focal 60%-70% distal left anterior descending artery stenosis. Cardiac MRI (CMR) was done for evaluation of viability which showed a large pseudoaneurysm which was missed on TTE and left ventriculogram. Our case demonstrates the increasing importance of cardiac MRI in the diagnosis of left ventricular pseudoaneurysm. In our case left ventricular pseudoaneurysm was missed on TTE and left ventriculogram. It was diagnosed on CMR which was ordered for evaluation of myocardium viability.

Utilization and adverse outcomes of percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation in the United States: influence of hospital volume.

BACKGROUND: Safety data on percutaneous left atrial appendage closure arises from centers with considerable expertise in the procedure or from clinical trial, which might not be reproducible in clinical practice. We sought to estimate the frequency and predictors of adverse outcomes and costs of percutaneous left atrial appendage closure procedure in the US. METHODS AND RESULTS: The data were obtained from the Nationwide Inpatient Sample from the years 2006 to 2010. The Nationwide Inpatient Sample is the largest all-payer inpatient data set in the US. Complications were calculated using patient safety indicators and International Classification of Diseases-Ninth Revision, Clinical Modification codes. Annual hospital volume was calculated using unique hospital identifiers. Weights provided by the Nationwide Inpatient Sample were used to generate national estimates. A total of 268 (weighted=1288) procedures were analyzed. The overall composite rate of mortality or any adverse event was 24.3% (65), with 3.4% patients required open cardiac surgery after procedure. Average length of stay was 4.61±1.05 days and cost of care was 26,024±34,651. Annual hospital procedural volume was significantly associated with reduced complications and mortality (every unit increase: odds ratio, 0.89; 95% confidence interval, 0.85-0.94; P<0.001), decrease in length of stay (every unit increase: hazard ratio, 0.95; 95% confidence interval, 0.92-0.98; P<0.001) and cost of care (every unit increase: hazard ratio, 0.96; 95% confidence interval, 0.93-0.98; P<0.001). CONCLUSIONS: Our study demonstrates that the frequency of inhospital adverse outcomes associated with percutaneous left atrial appendage closure is higher in the real-world population than in clinical trials. We also demonstrate that higher annual hospital volume is associated with safer procedures, with lower length of stay and cost.

Neutrophil lymphocyte ratio significantly improves the Framingham risk score in prediction of coronary heart disease mortality: insights from the National Health and Nutrition Examination Survey-III.

BACKGROUND: Neutrophil lymphocyte ratio (NLR) has been shown to predict cardiovascular events in several studies. We sought to study if NLR predicts coronary heart disease (CHD) in a healthy US cohort and if it reclassifies the traditional Framingham risk score (FRS) model. METHODS: We performed post hoc analysis of National Health and Nutrition Examination Survey-III (1998-94) including subjects aged 30-79 years free from CHD or CHD equivalent at baseline. Primary endpoint was death from ischemic heart disease. NLR was divided into four categories: <1.5, ≥1.5 to <3.0, 3.0-4.5 and >4.5. Statistical analyses involved multivariate Cox proportional hazards models as well as discrimination, calibration and reclassification. RESULTS: We included 7363 subjects with a mean follow up of 14.1 years. There were 231 (3.1%) CHD deaths, more in those with NLR>4.5 (11%) compared to NLR<1.5 (2.4%), p<0.001. Adjusted hazard ratio of NLR>4.5 was 2.68 (95% CI 1.07-6.72, p=0.035). There was no significant improvement in C-index (0.8709 to 0.8713) or area under curve (0.8520 to 0.8531) with addition of NLR to FRS model. Model with NLR was well calibrated with Hosmer-Lemeshow chi-square of 8.57 (p=0.38). Overall net reclassification index (NRI) was 6.6% (p=0.003) with intermediate NRI of 10.1% (p<0.001) and net upward reclassification of 5.6%. Absolute integrated discrimination index (IDI) was 0.003 (p=0.039) with relative IDI of 4.3%. CONCLUSIONS: NLR can independently predict CHD mortality in an asymptomatic general population cohort. It reclassifies intermediate risk category of FRS, with significant upward reclassification. NLR should be considered as an inflammatory biomarker of CHD.

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.

Optimal blood pressure in patients with atrial fibrillation (from the AFFIRM Trial).

Many medications used to treat atrial fibrillation (AF) also reduce blood pressure (BP). The relation between BP and mortality is unclear in patients with AF. We performed a post hoc analysis of 3,947 participants from the Atrial Fibrillation Follow-Up Investigation of Rhythm Management trial. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline and follow-up were categorized by 10-mm Hg increments. The end points were all-cause mortality (ACM) and secondary outcome (combination of ACM, ventricular tachycardia and/or fibrillation, pulseless electrical activity, significant bradycardia, stroke, major bleeding, myocardial infarction, and pulmonary embolism). SBP and DBP followed a "U-shaped" curve with respect to primary and secondary outcomes after multivariate analysis. A nonlinear Cox proportional hazards model showed that the incidence of ACM was lowest at 140/78 mm Hg. Subgroup analyses revealed similar U-shaped curves. There was an increased ACM observed with BP <110/60 mm Hg (hazard ratio 2.4, p <0.01, respectively, for SBP and DBP). In conclusion, in patients with AF, U-shaped relation existed between BP and ACM. These data suggest that the optimal BP target in patients with AF may be greater than the general population and that pharmacologic therapy to treat AF may be associated with ACM or adverse events if BP is reduced to <110/60 mm Hg.

Percutaneous aortic balloon valvotomy in the United States: a 13-year perspective.

BACKGROUND: We determined the contemporary trends of percutaneous aortic balloon valvotomy and its outcomes using the nation's largest hospitalization database. There has been a resurgence in the use of percutaneous aortic balloon valvotomy in patients at high surgical risk because of the development of less-invasive endovascular therapies. METHODS: This is a cross-sectional study with time trends using the Nationwide Inpatient Sample database between the years 1998 and 2010. We identified patients using the International Classification of Diseases, 9th Revision, Clinical Modification procedure code for valvotomy. Only patients aged more than 60 years with aortic stenosis were included. Primary outcome included in-hospital mortality, and secondary outcomes included procedural complications and length of hospital stay. RESULTS: A total of 2127 percutaneous aortic balloon valvotomies (weighted n = 10,640) were analyzed. The use rate of percutaneous aortic balloon valvotomy increased by 158% from 12 percutaneous aortic balloon valvotomies per million elderly patients in 1998-1999 to 31 percutaneous aortic balloon valvotomies per million elderly patients in 2009-2010 in the United States (P < .001). The hospital mortality decreased by 23% from 11.5% in 1998-1999 to 8.8% in 2009-2010 (P < .001). Significant predictors of in-hospital mortality were the presence of increasing comorbidities (P = .03), unstable patient (P < .001), any complication (P < .001), and weekend admission (P = .008), whereas increasing operator volume was associated with significantly reduced mortality (P = .03). Patients who were admitted to hospitals with the highest procedure volume and the highest volume operators had a 51% reduced likelihood (P = .05) of in-hospital mortality when compared with those in hospitals with the lowest procedure volume and lowest volume operators. CONCLUSION: This study comprehensively evaluates trends for percutaneous aortic balloon valvotomy in the United States and demonstrates the significance of operator and hospital volume on outcomes.