Single- and multi-site pacing strategies for optimal cardiac resynchronization therapy: impact on device longevity and therapy cost.

BACKGROUND: Multiple left ventricular pacing strategies have been suggested for improving response to cardiac resynchronization therapy (CRT). However, these programming strategies may sometimes entail accepting configurations with high pacing threshold and accelerated battery drain. We assessed the feasibility of predefined pacing programming protocols, and we evaluated their impact on device longevity and their cost-impact. METHODS: We estimated battery longevity in 167 CRT-D patients based on measured pacing parameters according to multiple alternative programming strategies: single-site pacing associated with lowest threshold, non-apical location, longest interventricular delay, and pacing from two electrodes. To determine the economic impact of each programming strategy, we applied the results of a model-based cost analysis using a 15-year time horizon. RESULTS: Selecting the electrode with the lowest threshold resulted in a median device longevity of 11.5 years. Non-apical pacing and interventricular delay maximization were feasible in most patients and were obtained at the price of a few months of battery life. Device longevity of > 10 years was preserved in 87% of cases of non-apical pacing and in 77% on pacing at the longest interventricular delay. The mean reduction in battery life when the second electrode was activated was 1.5 years. Single-site pacing strategies increased the therapy cost by 4-6%, and multi-site pacing by 12-13%, in comparison with the lowest-cost scenario. CONCLUSIONS: Modern CRT-D systems ensure effective pacing and allow multiple optimization strategies for maximizing service life or for enhancing effectiveness. Single- or multi-site pacing strategies can be implemented without compromising device service life and at an acceptable increase in therapy cost.

Mortality after cardioverter-defibrillator replacement: Results of the DECODE survival score index.

BACKGROUND: Device replacement is the ideal time to reassess health care goals regarding continuing implantable cardioverter-defibrillator (ICD) therapy. Only few data are available on the decision making at this time. OBJECTIVES: The goals of this study were to identify factors associated with poor prognosis at the time of ICD replacement and to develop a prognostic index able to stratify those patients at risk of dying early. METHODS: DEtect long-term COmplications after implantable cardioverter-DEfibrillator replacement (DECODE) was a prospective, single-arm, multicenter cohort study aimed at estimating long-term complications in a large population of patients who underwent ICD/cardiac resynchronization therapy - defibrillator replacement. Potential predictors of death were investigated, and all these factors were gathered into a survival score index (SUSCI). RESULTS: We included 983 consecutive patients (median age 71 years (63-78)); 750 (76%) were men, 537 (55%) had ischemic cardiomyopathy; 460 (47%) were implanted with cardiac resynchronization therapy - defibrillator. During a median follow-up period of 761 days (interquartile range 628-904 days), 114 patients (12%) died. In multivariate Cox regression analysis, New York Heart Association class III/IV, ischemic cardiomyopathy, body mass index < 26 kg/m2, insulin administration, age ≥ 75 years, history of atrial fibrillation, and hospitalization within 30 days before ICD replacement remained associated with death. The survival score index showed a good discriminatory power with a hazard ratio of 2.6 (95% confidence interval 2.2-3.1; P < .0001). The risk of death increased according to the severity of the risk profile ranging from 0% (low risk) to 47% (high risk). CONCLUSION: A simple score that includes a limited set of variables appears to be predictive of total mortality in an unselected real-world population undergoing ICD replacement. Evaluation of the patient's profile may assist in predicting vulnerability and should prompt individualized options, especially for high-risk patients.

Access to magnetic resonance imaging of patients with magnetic resonance-conditional pacemaker and implantable cardioverter-defibrillator systems: results from the Really ProMRI study.

Aims: The Really ProMRI study evaluates magnetic resonance imaging (MRI) access for patients with cardiac implantable electronic devices (CIEDs) as well as the performance of magnetic resonance (MR)-conditional leads when undergoing MRI. Methods and results: Patients either with an MR-conditional pacemaker or implantable defibrillator (ICD) system or with at least a component (device or one or more leads) from an MR-conditional system, were asked to fill in a questionnaire when they were referred to a MR scan. The rate of prescription, denial, or execution of MR examinations was evaluated in a 1-year follow-up visit. In total, 555 patients [median age (interquartile range) 72.2 (62.2-78.6); 72% male] were enrolled, 49% (270) with a pacemaker, 51% (285) with an ICD system. Five-hundred and ten patients completed the follow-up period. A total of 37 MRI referrals were reported in 35 patients, with a consequent event rate of 7.0/100 patient-years (CI, 4.9-9.7). Fourteen were denied, while 23 [66%; (CI, 48-81%)] were performed. The number of patients with MR referrals was not statistically different between pacemaker and ICD groups (21 vs. 14; P = 0.178). The rate of scans performed was higher in the pacemaker subjects (19/23 vs. 4/14, P = 0.003), while it was similar between patients with or without a complete MR-conditional system (19/30 vs. 4/7, P = 0.606). Conclusion: In this study, we reported a 7.0/100 patient-year's event rate of MR prescriptions in CIED patients. Many examinations were denied, despite MR-conditional systems, especially in ICD patients. Regulatory and cultural changes are needed to allow wider access to MR imaging in CIED patients with MR-conditional systems.

Postprocedural management of patients after transcatheter aortic valve implantation procedure with self-expanding bioprosthesis.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) carries higher risk of post-procedural adverse events than conventional percutaneous cardiovascular interventions. We report our experience about postoperative management protocol adopted in our Division. METHODS: One hundred and ten patients underwent TAVI and 108 were transferred to the cardiac intensive care unit (CICU) after procedure. During the first 48 hours, vital parameters were monitored continuously. Close attention was given to rhythm and atrio-ventricular conduction disturbances, systemic blood pressure, fluid balance and vascular accesses. RESULTS: The most common complications were renal impairment (21.3%), femoral artery pseudo-aneurysms (FAP) (11%), new complete atrioventricular block (20.3 %), cerebral vascular accident (4.5%) and cardiac perforation due to temporary pacemaker lead (1.8%). Ultrasound-guided compression repair was considered the first line treatment for FAP, but in 6 cases surgical treatment was immediately performed due to the rapid expansion of FAP. Complete atrio-ventricular block occurred in 22 patients (20.3 %) within the first 24 hours after TAVI and a permanent pacemaker was implanted in 21 patients (19.1%). Acute kidney injury occurred in 18 patients (35%) with pre-procedural chronic renal failure and in 5 patients (9%) without preoperative renal dysfunction. CONCLUSIONS: After TAVI, cardiovascular complications are common and therefore accurate standardized management of patients in CICU during the first 48 hours is mandatory to early detect and manage complications and to decrease the rate of adverse events and the length of in-hospital stay. © 2010 Wiley-Liss, Inc.

Early discharge in acute myocardial infarction after clinical and angiographic risk assessment.

BACKGROUND: Acute myocardial infarction (AMI) management aims to ensure the best care for patients while reducing hospital stay. The aim of this study was to evaluate feasibility and safety of early discharge (defined as discharge between 48 and 72 h from AMI) in low-risk patients after uncomplicated infarction. METHODS: We prospectively evaluated 321 patients (age: 59 +/- 11.7), who were admitted for AMI between February 2004 and August 2005 and assigned to 'low'-risk and 'high'-risk groups according to clinical and angiographic criteria. Low-risk patients were discharged between 48 and 72 h from admission. After discharge, all patients were re-evaluated after 1 week, 6 weeks and 6 months for AMI. We also retrospectively considered a control group of 68 low-risk patients with AMI admitted to our Coronary Intensive Care Unit (CICU) in the previous 4 months before the beginning of the study with standard discharge after at least 7 days of hospital stay. RESULTS: No events were detected in the first week after discharge. In low-risk patients, the cumulative major adverse event rate was 0.6% after 6 weeks, whereas in high-risk patients, the rate was 9% (P < or = 0.01). After 6 months, in the low-risk group, the cumulative major adverse event rate was 2%, whereas in the high-risk group, it was 10% (P < or = 0.01). The control group showed a cumulative major adverse event rate of 1.5% after 6 months, with no statistically significant difference between controls and low-risk patients. The type of AMI did not influence risk assessment and clinical outcome. CONCLUSION: Our data support the short-term safety and cost-effectiveness of early discharge in patients with uncomplicated AMI, treated with successful percutaneous coronary intervention.