Srikanth Vallurupalli

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.

Intradialytic exercise training reduces oxidative stress and epicardial fat: a pilot study

BACKGROUND Cardiovascular disease (CVD) mortality rates are greatly elevated in chronic kidney disease patients receiving maintenance haemodialysis therapy. The purpose of this study was to evaluate the efficacy of intradialytic endurance exercise training on novel risk factors that may contribute to this excessive CVD risk. METHODS Seventeen haemodialysis patients were randomized to either an intradialytic exercise training (cycling) group (EX; n = 8) or a non-exercising control group (CON; n = 9) for 4 months. At baseline and following the intervention, we measured serum parameters related to CVD risk and renal function, used echocardiography to measure variables related to cardiac structure and function and assessed physical performance by a validated shuttle walk test. RESULTS Performance on the shuttle walk test increased by 17% in EX (P < 0.05), but did not change in CON. There was no change in serum lipids or inflammatory markers (C-reactive protein, interleukin-6) in either group. Serum thiobarbituric acid reactive substances, a marker of oxidative stress, were reduced by 38% in EX (P < 0.05), but did not change in CON. In addition, serum alkaline phosphatase (ALP), a putative risk factor for vascular calcification, was reduced by 27% in EX (P < 0.05), but did not change in CON. There was no change in left atrial volume, left ventricular mass or myocardial performance index in either group. However, the thickness of the epicardial fat layer was reduced by 11% in EX (P < 0.05), but did not change in CON. Furthermore, the change in physical performance was inversely correlated to the change in epicardial fat (r = -0.63; P = 0.03). CONCLUSIONS These results suggest that endurance exercise training may improve CVD risk in haemodialysis patients by decreasing novel risk factors including serum oxidative stress, ALP and epicardial fat.

Impact of Hepatitis C Seropositivity on the Risk of Coronary Heart Disease Events

Chronic infections have been shown to enhance atherogenicity. However, the association between chronic hepatitis C (HCV) and coronary heart disease (CHD) remains controversial. We examined the risk for CHD events in patients with HCV with an emphasis on the risk of CHD events with active infection. We conducted a retrospective cohort study using the Enterprise Data Warehouse at the University of Arkansas for Medical Sciences. HCV positive and negative patients were identified based on serology and incident CHD events were studied. Patient characteristics at entry were compared either by analysis of variance/F-test (continuous variables) or by a Chi-squared test (categorical variables). The joint effect of risk factors for incident CHD was evaluated using logistic regression. A total of 8,251 HCV antibody positive, 1,434 HCV RNA positive and 14,799 HCV negative patients were identified. HCV antibody and RNA positive patients had a higher incidence of hypertension, diabetes mellitus, obesity and chronic lung disease, but lower serum cholesterol levels compared to HCV negative patients (p< 0.001). HCV seropositive patients had a higher incidence of CHD events when compared to controls (4.9% vs. 3.2%, p<0.001). In the HCV cohort, patients with detectable HCV RNA had a significantly higher incidence of CHD events when compared to patients who were only HCV antibody positive with no detectable RNA (5.9% vs. 4.7%, p=0.04). In multivariate logistic regression analysis, both HCV antibody positivity (OR 1.32, 95% CI 1.09-1.60, p<0.001) and HCV RNA positivity (OR 1.59, 95% CI 1.13-2.26, p<0.001) were independent risk factors for incident CHD events. In conclusion, there is increased incidence of CHD events in HCV seropositive patients and the incidence is much higher in patients with detectable HCV RNA when compared to patients with remote infection who are only antibody positive. Lipid profile does not appear to be a good cardiovascular risk stratification tool in HVC patients.

Optimization of stent implantation using a high pressure inflation protocol

High‐pressure inflation is the universal standard for stent deployment but a specific protocol for its use is lacking. We developed a standardized “pressure optimization protocol” (POP) using time to inflation pressure stability as an endpoint for determining the required duration of stent inflation. Objectives: The primary study purpose was to determine the stent inflation time (IT) in a large patient cohort using the standardized inflation protocol, to correlate various patient and lesion characteristics with IT, and ascertain in an in vitro study the time for pressure accommodation within an inflation system.

Clinical and prognostic utility of cardiovascular magnetic resonance imaging in myeloma patients with suspected cardiac amyloidosis

OBJECTIVES AL amyloidosis affects up to 30% of patients with multiple myeloma (MM), and cardiac involvement is associated with worse outcomes. Traditional screening modalities including EKG, echocardiography and biomarkers have limited value. The aim of this study was to evaluate the clinical and prognostic value of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) imaging in patients with plasma cell dyscrasias and suspected cardiac amyloidosis (CA). METHODS A total of 251 consecutive patients with plasma cell dyscrasias who underwent CMR were enrolled in this study. Primary endpoint was all cause mortality. Clinical, ECG, echocardiographic, biomarker and CMR predictors of mortality were analyzed. RESULTS Mean age of population was 63 ± 10 years, 36% females and 19% African Americans. During a median follow-up duration of 28 months (IQR 5-56), there were 97 deaths (39%). Patients who died were more likely to have diabetes (28% vs. 14%; P = 0.03), CAD (28% vs. 16%; P = 0.04) and CKD (33% vs. 21%; P = 0.04). With endomyocardial biopsy as the gold standard (42 (17%) patients), amyloid pattern on CMR (LGE+) had sensitivity and negative predictive values of 100%; specificity and positive predictive values of 80 and 81% with an AUC 0.9 for CA. History of CAD (HR 1.64, 95% CI 1.01-2.6; P = 0.04), brain natriuretic peptide (HR 1.0003 95% CI 1.0001-1.0006; P = 0.004) and LGE + (HR 1.72, 95% CI 1.05-2.8; P = 0.02) were independent predictors of mortality. LGE+ possessed incremental prognostic value over clinical, laboratory and echocardiographic variables for mortality prediction. CONCLUSIONS CMR is a clinically useful tool for diagnosis and prognostication in myeloma patients with suspected CA.

Infection and the Risk of Topical Anesthetic Induced Clinically Significant Methemoglobinemia after Transesophageal Echocardiography

Background: Methemoglobinemia is a recognized complication of topical anesthesia with benzocaine during transesophageal echocardiography (TEE). Though several risk factors have been described, the importance of individual factors is not known. We performed a retrospective study to identify determinants of the risk of methemoglobinemia. Materials and methods: All patients who underwent TEE with benzocaine topical anesthesia between June 2005 and June 2007 were included in this retrospective study. Results: Of the 886 patients who were included in the study, 140 had active infection (15.8%). The incidence of methemoglobinemia in this group was 2.9% (vs. 0%, P < 0.001). Compared to those without infection, patients in the active infection group were more likely to have a lower hemoglobin (P < 0.001), serum albumin level (P < 0.001), glomerular filtration rate less than 60 ml/min per 1.73 m2 (P < 0.001), higher rates of dialysis (P < 0.001), a higher incidence of malignancy (P = 0.01), and increased use of acetaminophen and sulfa drugs (P < 0.001). However, multivariate logistic regression analysis did not identify any statistically significant covariates. Conclusion: In conclusion, patients with an active systemic infection who undergo TEE are at a higher risk of methemoglobinemia. However, none of the risk factors for methemoglobinemia including active infection reached statistical significance in the regression analysis which has to be interpreted with caution in view of the low event rate. (Echocardiography 2010;27:318‐323)

Safety of Subcutaneous Octreotide in Patients with Sulfonylurea-Induced Hypoglycemia and Congestive Heart Failure

Objective: To report the safe use of subcutaneous octreotide in the treatment of sulfonylurea-induced hypoglycemia in 2 patients with severe congestive heart failure. Case Summary: Two patients with congestive heart failure with systolic dysfunction presented with severe hypoglycemia (blood glucose level: patient 1, 31 mg/dL; patient 2, 36 mg/dL) secondary to sulfonylurea agents. The mechanism of hypoglycemia was poor oral intake and prolonged half-life of the drugs due to renal failure. Hypoglycemia was refractory to glucose supplementation. Patient 1 received 2 doses of octreotide 50 μg subcutaneously 12 hours apart, with resolution of hypoglycemia (blood glucose level: <33 mg/dL before administration of octreotide, 62 mg/dL after first dose, 121 mg/dL after second dose). Patient 2 received an initial dose of octreotide 25 μg subcutaneously; hypoglycemia persisted after this dose, and the patient was given 2 doses of 50 μg subcutaneously 12 hours apart, leading to resolution of hypoglycemia (blood glucose level: 57 mg/dL before administration of octreotide, 80 mg/dL after first dose, 85 mg/dL after second dose, 146 mg/dL after third dose). Resolution of hypoglycemia with octreotide treatment obviated the need for prolonged intravenous dextrose infusions. No local or systemic adverse effects, especially cardiac adverse events, were noted during the course of treatment. Discussion: Octreotide is considered the antidote for sulfonylurea-induced hypoglycemia. It may be especially useful in patients with congestive heart failure who may not tolerate intravenous infusions of dextrose. The package insert cautions of the occurrence of cardiac adverse effects such as bradycardia, heart block, and worsening heart failure. Patients with heart failure may theoretically be at a higher risk of these adverse effects due to the concurrent use of atrioventricular blocking agents. However, a review of current literature reveals that the adverse effect profile depends on the route, dose, and formulation of the octreotide used along with the clinical indication. These adverse effects may not be clinically significant with the doses used for treatment of sulfonylurea-induced hypoglycemia and the benefits of the drug may outweigh the risks. Conclusions: In these cases, octreotide was safely and effectively used in the treatment of sulfonylurea-induced hypoglycemia in patients with congestive heart failure by adhering to dosing guidelines and close monitoring.

Controversies in postoperative atrial fibrillation after noncardiothoracic surgery: clinical and research implications

Post operative atrial fibrillation after non‐cardiothoracic surgery is an increasingly common problem. There is little high quality data to guide clinicians in risk prediction as well as short term and long term management. There appears to be a significant risk of recurrent atrial fibrillation and stroke but effective screening strategies have not been tested. In this commentary, we delineate various controversies in the management of post operative atrial fibrillation and briefly review the available evidence. Prospective studies in this clinically important area of cardiology should be encouraged.

A Change of Heart: Reopening of a Foramen Ovale

Platypnea-orthodeoxia is a rare syndrome characterized by dyspnea and hypoxemia that is exacerbated by assuming an upright position. The most common cause is intracardiac shunting through an atrial septal defect or patent foramen ovale (PFO). We present a 63-year-old man with dyspnea after right pneumonectomy for lung cancer, who was found to have a large PFO with right-to-left shunt in the presence of normal right-sided pressures. Percutaneous closure of the PFO led to resolution of symptoms.

Risk of acquired methemoglobinemia with different topical anesthetics during endoscopic procedures

Introduction Methemoglobinemia is a recognized complication of the use of topical anesthetic sprays. The true scope of the problem or the risk with different topical anesthetic sprays and endoscopic procedures is unknown. Methods We retrospectively identified all cases of methemoglobinemia that occurred in a university affiliated community hospital from 2001 to 2007. Results Eleven cases of methemoglobinemia were identified over the 6-year period. Nine (82%) occurred with use of benzocaine spray during transesophageal echocardiography (TEE). Patients who developed methemoglobinemia secondary to the topical anesthetic spray compared to other causes were more likely to be older, have lower mean hemoglobin levels (10.5 ± 0.5 g/dL vs 11.3 ± 0.0 g/dL), and a higher mean methemoglobin concentration at diagnosis (40.8% ± 5.2% vs 24% ± 10%). However, only age reached statistical significance (P = 0.004). Conclusion In a university-affiliated community hospital, topical anesthetic sprays account for most of the burden of methemoglobinemia. Benzocaine use in the context of TEE caused more methemoglobinemia compared to lidocaine and other endoscopic procedures. This observation supports previous data and findings deserve further study.