Niyada Naksuk

Implantable Cardioverter-Defibrillators in Patients With COPD

BACKGROUND COPD is a common comorbidity in heart failure. The efficacy of implantable cardioverter-defibrillator (ICD) therapy has not been determined in patients with heart failure and COPD. METHODS We examined the incidence of ICD shocks and mortality in 628 consecutive patients who underwent defibrillator implantation at the Minneapolis Veterans Affairs Medical Center from 2006 to 2010. RESULTS The mean age of the patients was 67 ± 10 years, and 99% were men. Patients with COPD (n = 246 [39%]) were functionally more limited (P < .0001) and more likely to have an ICD for primary prevention of sudden death (P = .04) than those without COPD. Over a median 4.1 years (interquartile range [IQR] 2.2-5.7) of follow-up, patients with COPD had a higher incidence of appropriate shocks than those without COPD (29% vs 17%; P < .0001), whereas the incidence of inappropriate shocks was similar (9% vs 10%, P = .61). In multivariable analysis, COPD was associated with a twofold increase in the odds of an appropriate ICD shock (95% CI, 1.3-2.9; P = .001). Incidence of ICD shocks did not vary with severity of COPD. Although all-cause mortality was higher in patients with COPD than in those without COPD (29% vs 21%, P = .029), 1-year mortality (5.3% vs 2.6%, P = .08) and the average time from first appropriate ICD shock to death was comparable (median, 2.3 [IQR, 1.2-4.4] vs 2.8 [IQR, 1.4-5.3] years; P = .29). CONCLUSIONS Patients with COPD have a higher incidence of ICD shocks than those without COPD and appear to benefit from ICD therapy.

Beating Heart Validation of Safety and Efficacy of a Percutaneous Pericardiotomy Tool

Epicardial procedures frequently require pericardial manipulation. We aimed to develop a nonsurgical percutaneous pericardial modification tool that may (1) facilitate epicardial‐based procedures by enabling adhesiolysis or (2) attenuate the myocardial constraining effect of the pericardium.

Adherence to diagnostic guidelines of hepatocellular carcinoma: 12-year experience in a veterans affairs medical center.

Background Noninvasive diagnostic criteria for cirrhotic hepatocellular carcinoma (HCC) were first established in 2001 by the European Association for the Study of the Liver. Objectives The aim of this study was to evaluate adherence to the HCC diagnostic algorithm over time and identify factors associated with nonadherence. Methods Between 2001 and 2013, 224 consecutive cirrhotic HCC cases were retrospectively reviewed. Nonadherent biopsy (NAB) was defined as cases diagnosed either by biopsy despite meeting noninvasive criteria for HCC or by biopsy in place of an optional second imaging modality. Nonadherent nonbiopsy (NANB) was defined as cases diagnosed without performing biopsy when noninvasive criteria were not met. Factors associated with nonadherence were identified using multivariate analysis. Results Nonadherence rate decreased from 52 to 30% over the study period (P=0.003). Among all patients, there were 34% NAB and 13% NANB cases. Compared with the adherence group, both NAB and NANB groups were likely to undergo only computed tomography scanning [odds ratio (OR) 3.08, 95% confidence interval (CI) 1.71–5.66 and OR 3.18, 95% CI 1.28–8.27, respectively] and were less likely to undergo MRI (OR 0.29, 95% CI 0.16–0.53 and OR 0.26, 95% CI 0.10–0.66, respectively). In addition, the NAB group was less likely to be presented in a multidisciplinary tumor conference (OR 0.12, 95% CI 0.02–0.61). Conclusion This is the first study to report adherence to HCC diagnostic guidelines over time in a veteran hospital. Despite overall improvement, nonadherence at the present time is still high (∼30%). Underutilization of MRI and the multidisciplinary tumor conference is associated with nonadherence, representing a potential area for improvement.

Potentially modifiable factors of dofetilide-associated risk of torsades de pointes among hospitalized patients with atrial fibrillation

PurposeThere is a significant variation in the clinical approach of initiation and dose adjustment of dofetilide in atrial fibrillation (AF). Excessive QT prolongation could predispose patients to torsades de pointes (TdP), which can be fatal.MethodsWe performed a retrospective case-control study at Mayo Clinic Rochester (January 1, 2003 to December 31, 2016). “TdP risk” cases were defined as patients on dofetilide therapy for AF with subsequent TdP or excessive QTc prolongation requiring dose reduction or discontinuation (N = 31). A control group was matched 1:1 with cases by age, gender, year of admission, and dofetilide dose (N = 31).ResultsUsing multivariate regression analysis, independent predictors of TdP risk included baseline QTc exceeding recommendations (adjusted odd ratio [AOR] 4.57; P = 0.023); underlying AF with rapid ventricular rate (AOR 16.95; P = 0.004); and diuretic therapy for acute heart failure (AOR 8.42; P = 0.007). Poor inter-observer agreement was identified among QT interval measurement in patients with AF and rapid ventricular rate compared to those in rate controlled AF or sinus rhythm. TdP risk cases receiving diuretics for acute heart failure had a significant decline in creatinine clearance than controls, although serum electrolytes and replacement did not differ among the two groups.ConclusionsExcessive QTc prolongation and AF with rapid ventricular rate at time of dofetilide initiation (likely due to difficulty in measuring QT intervals), and diuretic therapy for acute heart failure were independent factors for dofetilide-related TdP risk. Based on these data, possible preventive strategies could be adapted for safety protocols among hospitalized patients.

Right Ventricular Dysfunction and Long-Term Risk of Sudden Cardiac Death in Patients With and Without Severe Left Ventricular Dysfunction

Background: Right ventricular systolic dysfunction (RVD) often coexists with various cardiopulmonary diseases. However, the association between RVD and risk of sudden cardiac death (SCD) has not been well studied. This study examined the risk of SCD associated with RVD in patients with heterogeneous underlying cardiac diseases. Methods: The Mayo Clinic cardiac care unit database included 5463 consecutive patients with complete echocardiographic evaluation to assess right ventricular systolic function and RVD severity. Prospective surveillance follow-up was obtained for all patients. SCD was adjudicated when a malignant ventricular arrhythmia was documented as the primary rhythm leading to death. Results: The prevalence of mild RVD and moderate-severe RVD was 14.9% and 17.1%, respectively. Patients with RVD were more likely to have a history of congestive heart failure, cardiac arrest, pulmonary disease, and lower baseline left ventricular ejection fraction compared with those with normal right ventricular systolic function. During a median follow-up of 14 months, the incidence of SCD was highest in patients with moderate-severe RVD (7.4% versus 4.4% in mild RVD versus 1.6% in normal right ventricular function; P<0.001). After adjustment for baseline characteristics, mild RVD (adjusted hazard ratio, 1.57; P=0.046) and moderate-severe RVD (adjusted hazard ratio, 1.91; P=0.006) were independently associated with an increased risk of SCD. Moderate-severe RVD remained an independent predictor of SCD for patients with left ventricular ejection fraction >35% without or with preexisting implantable cardioverter-defibrillator (adjusted hazard ratio, 4.12; P=0.003 and adjusted hazard ratio, 5.04; P<0.001, respectively). Conclusions: Presence of RVD in patients with a history of preexisting cardiac disease is an independent predictor of SCD irrespective of left ventricular ejection fraction.

Initial Experience with the BioSig PURE EP™ Signal Recording System: An Animal Laboratory Experience

Current signal recording and processing systems have come a long way since their initial inception and use. There is, however, still ample scope for improvement, not only in the troubleshooting of their limitations, but also in the expansion of the boundaries in the recording of intracardiac signals. Here, we recount our experience with the use of the PURE EP™ signal recording system (BioSig Technologies, Inc., Minneapolis, MN, USA) in the animal laboratory.