Pulmonary fluid overload monitoring in heart failure patients with single and dual chamber defibrillators.

AIMS: Heart failure has a relevant healthcare impact. Monitoring of pulmonary fluid overload (PFO), measured by intrathoracic impedance, has been proposed to alert to heart failure worsening before symptoms become patent. The aim of our research was to evaluate whether PFO diagnostics reduce heart failure hospitalizations in heart failure patients receiving single-chamber or dual-chamber implantable cardioverter-defibrillator (ICD) for primary prevention of sudden death. METHODS: Twenty-five Italian cardiological centers prospectively followed 221 ICD patients (86% men, 66 ±â€Š11 years, 79% New York Heart Association II and left ventricular ejection fraction 28 ±â€Š5%), of whom 123 received an ICD with PFO monitoring (diagnostics group) and 98 an ICD without such a diagnostics (control group). The association of each patient to a group was assigned a priori, independently of patients' characteristics but based on regional device allocation policies. RESULTS: Patient clinical characteristics and observation period were similar between groups. In a mean follow-up of 17 ±â€Š11 months, heart failure hospitalizations or emergency-room admissions occurred in eight (7%) patients of the diagnostics group and in 16 of the control group (16%; P = 0.02), with an incidence, measured by Kaplan-Meier analysis, of 23% at 2 years and 34% at 3 years in patients of the control group compared with 8% at 2 and 3 years in patients of the diagnostics group (Log rank test P = 0.044). CONCLUSION: Our data show that in heart failure patients receiving single-chamber or dual-chamber ICD, the use of intrathoracic impedance monitoring is associated with a significant reduction of heart failure hospitalizations. Our results support the hypothesis that PFO diagnostics improve the likelihood of timely detection of heart failure worsening.

Incidence and clinical relevance of uncontrolled ventricular rate during atrial fibrillation in heart failure patients treated with cardiac resynchronization therapy.

AIMS: Uncontrolled ventricular rate (VR) during atrial fibrillation (AF) may cause clinical deterioration in heart failure (HF) patients who need continuous biventricular pacing to achieve cardiac resynchronization therapy (CRT). We aimed at evaluating the association between AF, uncontrolled VR, and sub-optimal CRT, defined as low biventricular pacing percentage (BIVP%). METHODS AND RESULTS: All 1404 patients had HF, New York Heart Association (NYHA) ≥II, left ventricular ejection fraction (LVEF) ≤35%, and QRS ≥120 ms, and received an implantable CRT defibrillator (CRT-D). Occurrence of AF, VR during AF and lifetime BIVP% were estimated from device data. Ventricular rate during AF was defined as uncontrolled in patients with mean VR>80 bpm and maximum VR>110 bpm. Over a median follow-up of 18 months, AF was detected in 443 of 1404 patients (32%). In this sub-group of AF patients, VR during AF was uncontrolled in 150 of 443 patients (34%). Multivariate Cox regression analysis showed that age [hazard ratio (HR) = 1.03, 95% confidence interval (CI) = 1.00-1.06, P= 0.028], and uncontrolled VR [HR = 1.69 (CI = 1.01-2.83), P= 0.046] were the only independent predictors of clinical outcome, assessed by HF hospitalizations and death. The median lifetime BIVP% was 95% (25-75 percentile range 91-99%). Biventricular pacing percentage was significantly and inversely correlated to VR, decreasing by 7% for each 10 bpm increase in VR. Sub-optimal CRT, defined as BIVP% <95%, was predicted by the occurrence of persistent or permanent AF [odds ratio (OR) = 3.77, CI = 2.44-5.82, P< 0.001], and uncontrolled VR [OR = 2.25, CI = 1.35-3.73, P= 0.002]. CONCLUSION: Uncontrolled VR occurs in one-third of CRT-D patients, who experience AF, and is associated with HF hospitalizations and death and with sub-optimal CRT (lifetime BIVP%<95%).

Duration of P-wave is associated with atrial fibrillation hospitalizations in patients with atrial fibrillation and paced for bradycardia.

BACKGROUND: Atrial fibrillation (AF) is a common problem in pacemaker patients. We conducted a prospective observational study in patients paced for bradycardia with associated paroxysmal or persistent AF, to determine whether P-wave duration may stratify patients at higher risk for AF recurrences and AF-related hospitalizations. The patients were evaluated for the prevalence, cause, and predictors of hospitalization. METHODS: We studied 660 consecutive patients (50% male, 72 +/- 9 years) who received a dual-chamber pacemaker. Median value of baseline P-wave duration was equal to 100 ms (25%-75% quartile range equal to 80-120 ms). We used this cut-off to divide the patients into group A (P < or = 100 ms), composed of 385 (58.3%) patients, and group B (P>100 ms), composed of 275 (41.7%) patients. RESULTS: In a median follow-up of 19 months, 173 patients were hospitalized for all causes, 130 for cardiovascular causes, and 85 for AF-related hospitalizations. Multivariate logistic analysis showed that P-wave duration >100 ms identified patients at higher risk (OR = 1.6, 95% confidence interval (1.1-2.8), P = 0.044) for AF-related hospitalizations. Patients in group B (P > 100 ms) more frequently suffered AF-related hospitalizations (16.4% vs 10.4%, P = 0.02) and underwent more frequent cardioversions (14.5% vs 9.1%, P = 0.029) compared with group A (P < or = 100 ms). CONCLUSIONS: P-wave duration may define the risk of persistent AF requiring cardioversion or AF-related hospitalization in patients with a pacemaker for bradycardia with associated paroxysmal or persistent AF.

Primary prevention of sudden cardiac death: can we afford the cost of cardioverter-defibrillators? Data from the Search-MI Registry-Italian sub-study.

BACKGROUND: Large randomized trials show that in appropriately selected patients with left ventricular dysfunction, implantable cardioverter-defibrillators (ICDs) can improve overall survival at 2-5 years. Since direct implementation of the criteria used in the MADIT II and SCD-HeFT will lead to a marked rise in ICD implants, there is a growing fear that increased use of ICDs may cause a dramatic burden to health care systems. The ICD has traditionally been seen as an expensive form of treatment, which is difficult to accept at the first look. This is mainly due to the nonlinear character of the ICD investment, characterized by high initial expenditure, followed by a deferred pay-off in terms of clinical benefits. Cost-effectiveness analysis may help provide a different perspective on the problem of ICD cost, as may estimation of the daily cost of ICD treatment, assuming a time horizon of 5-7 years--a particularly interesting subject for further registry studies. METHODS AND RESULTS: Based on real expenditure data from 2002 to 2005, as recorded in the Search-MI Registry-Italian Sub-study of patients implanted on MADIT II indications, we estimated the daily costs associated with the device and leads. Over a 5-7 year time horizon, the average daily cost was estimated to be euro 4.60-euro 6.70. Translation of these figures into U.S. market conditions suggests a daily cost of around $7.90-$11.40. CONCLUSIONS: These findings appear useful to help evaluate the affordability of ICD in comparison with other therapeutic options in a context of limited available economic resources.