The lung impedance monitoring in treatment of chronic heart failure (the LIMIT-CHF study).

AIMS: To assess the usefulness of intrathoracic impedance monitoring (IIM) alerts in guiding empirical treatment of chronic heart failure (CHF) patients to prevent heart failure (HF) hospitalizations and unplanned HF care. METHODS AND RESULTS: Chronic heart failure patients with OptiVol or CorVue capable implantable cardioverter-defibrillators were randomized to either the active group (IIM alarm turned on and diuretic dose increased by 50% for 1 week in the event of alarm sounding) or the control group (IIM alarm turned off). The primary endpoint was the number of HF hospitalizations per patient at 1 year. The NYHA class, 6MWT, B-type natriuretic peptide (BNP), and MLWHF questionnaire score were collected at baseline and follow-up. Eighty patients were included and 71 reached 1-year follow-up. There were 1.7 ± 1.5 alerts in the active group and 1.1 ± 1.0 in the control group, P = 0.07. In the active group, 61% of alerts led to a diuretic dose increase. There was a total of 11 HF hospitalizations in the active group vs. 6 in the control group without significant differences in the number of episodes per patient (0.3 ± 0.9 vs. 0.2 ± 0.4, P = 0.95). There were no unplanned HF visits in the active group vs. 0.1 ± 0.3 per patient in the control group, P = 0.08. The total MLWHF scores were significantly increased at the final follow-up in the control group, whereas a trend towards reduction was observed in the active group. CONCLUSION: In this study, an empirical HF treatment guided by IIM alerts did not reduce emergency treatment of HF. However, it seems to have a positive impact on quality of life. CLINICAL TRIAL REGISTRATIONURL: http://www.clinicaltrials.gov. Unique identifier: NCT01320007.

Predictors of new onset atrial fibrillation in patients with heart failure.

INTRODUCTION: Stroke associated with atrial fibrillation (AF) is more frequent in heart failure. It is unknown what variables predict future AF in these patients and how AF might evolve over time. We investigated this in patients with implantable cardiac defibrillators (ICD) where AF detection is optimal. METHODS: Single centre, retrospective, observational cohort study. All ischaemic cardiomyopathy patients with dual chamber, primary prevention ICD implants between Aug 2003 and Dec 2009 were screened and included if at implant, they had no known AF history. Nine variables were analysed. AF was defined as any atrial tachyarrhythmia ≥180 bpm and ≥30 s. Multivariable, binary logistic regression models were built by adding variables significant in the univariate models. Variables were retained in the final multivariate models if p<0.05. RESULTS: n=197 met the inclusion criteria (85.8% male, median age: 66.8 years). After median follow-up for 2.8 years, 44.2% developed AF. After univariate analysis, the baseline variables associated with AF after implant were age, NYHA class and renal impairment (RI, defined eGFR<60 ml/min/1.73 m2) (p<0.05). After multivariable analysis, the only variable which was associated with AF was RI (HR: 2.04 (CI: 1.10-3.79)). Two baseline variables were independently associated with all-cause mortality: RI (HR: 2.42 (1.14-5.12)) and non-white ethnicity. CONCLUSION: RI at time of implant was independently associated with both future AF and all-cause mortality during long-term follow-up. RI was a stronger predictor of AF than age. Those patients with heart failure and RI should be regularly screened for asymptomatic AF, regardless of age, to ensure that stroke prophylaxis may be initiated.

Does ventricular dyssynchrony on echocardiography predict response to cardiac resynchronisation therapy? A randomised controlled study.

OBJECTIVE: To determine the value of echocardiography in predicting response to cardiac resynchronisation therapy (CRT). METHODS: This is a prospective randomised study that recruited patients with (group 1) and without (group 2) echocardiographic evidence of mechanical dyssynchrony. 73 heart failure patients (NYHA III-IV) with a requirement for an implantable cardioverter defibrillator, QRS ≥120 ms and LV ejection fraction (EF) <35% were studied. Group 1 patients received CRT-D (26 patients). Group 2 patients were randomised to CRT-D (group 2a: 23 patients) or implantable cardioverter defibrillator (group 2b: 21 patients). MAIN OUTCOME MEASURES: were peak oxygen consumption (VO(2)max), NYHA class, and echocardiography at baseline and at 6 months. RESULTS: 62% of group 1 patients achieved ≥1 ml/kg/min increase in VO(2)max at 6 months versus 50% in group 2a and 21% in group 2b (p=0.04). Group 1 patients showed significant improvements in VO(2)max (15.8±2 to 18.0±4 ml/kg/min, p=0.01), NYHA class (3.1±0.3 to 1.9±0.7, p<0.001) and EF (22±7% to 26±9%, p=0.02). Group 2a showed significant improvement in NYHA class (3.1±0.3 to 2.2±0.7, p<0.001) but no change in EF or VO(2)max. Group 2b showed no change in NYHA class or EF with a decline in VO(2)max (16.4±4 to 14.1±4, p=0.03). A significantly higher proportion of patients in group 2b showed ≥1 ml/kg/min deterioration in VO(2)max compared to group 2a (68% vs 23%, HR for group 2b: 2.4, 95% CI 1.2 to 4.8, p=0.005). CONCLUSIONS: The presence of echocardiographic dyssynchrony identifies patients who derive the most improvement from CRT. Patients without dyssynchrony also show more benefit and less deterioration with CRT than without and should not be denied CRT.

Ablation of supraventricular tachycardia in a 96 year old.

Atrioventricular nodal re-entrant tachycardia (AVNRT) is a common arrhythmia that is frequently encountered in clinical practice. Though more common in the younger population, it affects individuals of all ages. The elderly in particular are usually more symptomatic and more frequently require emergency treatment including urgent hospital admissions. We report on a 96-year-old lady who presented with troublesome supraventricular tachycardia that was difficult to control with drug treatment. Electrophysiologic testing revealed AVNRT that was ablated successfully using the standard technique with no complications. She continued to do well at follow-up 1 month after the ablation. This case highlights the need to routinely offer this highly effective technique as the first-line treatment to the elderly along the same indications as those commonly observed among younger patients.