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CRT Recipients (crt + recipient)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Response to Cardiac Resynchronization Therapy in Patients with Heart Failure and Renal Insufficiency

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2010
EVAN C. ADELSTEIN M.D.
Background: Renal insufficiency (RI) adversely impacts prognosis in heart failure (HF) patients, partly because renal and cardiac dysfunction are intertwined, yet few cardiac resynchronization therapy (CRT) studies have examined patients with moderate-to-severe RI. Methods: We analyzed 787 CRT-defibrillator (CRT-D) recipients with a glomerular filtration rate (GFR) measured prior to implant. Patients were grouped by GFR (in mL/min/1.73 m2): ,60 (n = 376), 30,59 (n = 347), and <30 (n = 64). Overall survival, changes in left ventricular (LV) ejection fraction and LV end-systolic diameter, and GFR change at 3,6 months were compared among CRT-D groups and with a control cohort (n = 88), also stratified by GFR, in whom LV lead implant was unsuccessful and a standard defibrillator (SD) was placed. All patients met clinical criteria for CRT-D. Results: Among CRT-D recipients, overall survival improved incrementally with higher baseline GFR (for each 10 mL/min/1.73 m2 increase, corrected hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.13,1.30, P < 0.0001). Survival among SD and CRT-D patients within GFR < 30 and GFR , 60 groups was similar, whereas CRT-D recipients with GFR 30,59 had significantly better survival compared to SD counterparts (HR 2.23, 95% CI 1.34,3.70; P = 0.002). This survival benefit was associated with improved renal and cardiac function. CRT recipients with GFR , 60 derived significant echocardiographic benefit but experienced a GFR decline, whereas those with GFR < 30 had no echocardiographic benefit but did improve GFR. Conclusions: CRT may provide the largest survival benefit in HF patients with moderate RI, perhaps by improving GFR and LV function. Severe baseline RI predicts poor survival and limited echocardiographic improvement despite a modest GFR increase, such that CRT may not benefit those with GFR < 30 mL/min/1.73 m2. CRT recipients with normal renal function derive echocardiographic benefit but no overall survival advantage. (PACE 2010; 850,859) [source]

Achieving Permanent Left Ventricular Pacing,Options and Choice

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2009
ERNEST W. LAU M.D.
Cardiac resynchronization therapy (CRT) requires permanent left ventricular (LV) pacing. Coronary sinus (CS) lead placement is the first line clinical approach but can be difficult or impossible; may suffer from a high LV pacing threshold, phrenic nerve stimulation, and dislodgement; and produces epicardial LV pacing, which is less physiological and hemodynamically effective and potentially more proarrhythmic than endocardial LV pacing. CS leads can usually be extracted with direct traction but may require use of extraction sheaths. Half of CS side branches previously used for lead placement may be unusable for the same purpose after successful lead extraction, and 30% of CS lead reimplantation attempts may fail due to exhaustion of side branches. Surgical epicardial LV lead placement is the more invasive second line approach, produces epicardial LV pacing, and has a lead failure rate of ,15% in 5 years. Transseptal endocardial LV lead placement is the third line approach, can be difficult to achieve, but produces endocardial LV pacing. The major concern with transseptal endocardial LV leads is systemic thromboembolism, but the risk is unknown and oral anticoagulation is advised. Among the new CRT recipients in the United States and Western Europe between 2003 and 2007, 22,798 patients may require CS lead revisions, 9,119 patients may have no usable side branches for CS lead replacement, and 1,800 patients may require surgical epicardial LV lead revision in the next 5 years. The CRT community should actively explore and develop alternative approaches to LV pacing to meet this anticipated clinical demand. [source]

Correlation of Electrical and Mechanical Reverse Remodeling after Cardiac Resynchronization Therapy

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2009
Swapna Kamireddy M.D.
Background: Cardiac resynchronization therapy (CRT) improves clinical outcome in many patients with refractory heart failure (HF). This study examined whether CRT is associated with reverse electrical remodeling by surface electrocardiogram (ECG). Methods: Consecutive CRT recipients at the University of Pittsburgh Medical Center with >90 days of follow-up were included in this analysis. ECG data were abstracted from medical records. Subjects with a relative increase of ,15% in left ventricular ejection fraction (LVEF) after CRT were considered responders. Results: A total of 113 patients (age 69 ± 11 years, men 70%, white 92%) were followed for a mean duration of 407 ± 290 (92,1439) days. Overall, LVEF increased after CRT (29 ± 13% vs 24 ± 9%; P < 0.01) and 50% of patients were responders. The mean native QRS interval among responders was higher than in nonresponders (163 ± 32 ms vs 148 ± 29 ms; P < 0.01). More than 3 months after CRT, there was no change in the paced QRS duration compared to baseline. Paced QRS duration, however, decreased among responders and increased among nonresponders and was significantly different by response status (P < 0.001). There was a significant correlation between increase in LVEF and decrease in paced QRS width in the overall population (r =,0.3; P < 0.01). Conclusions: Among responders to CRT, the paced QRS width decreases significantly, whereas it increases among nonresponders. Given the paced nature of the QRS, the improved conduction probably reflects enhanced cell-to-cell coupling after CRT as opposed to improved conduction within the His-Purkinje system. These findings have significant implications as to the mechanisms of benefit from CRT. [source]

Beta-blocker Utilization and Outcomes in Patients Receiving Cardiac Resynchronization Therapy

CLINICAL CARDIOLOGY, Issue 7 2010
Andrew Voigt MD
Introduction Optimal pharmacologic therapy (OPT) is considered a prerequisite to consideration for cardiac resynchronization therapy (CRT). Hypothesis Medications such as beta-blockers (BB) with demonstrated benefit in heart failure (HF) are being under utilized in patients receiving CRT. Methods Consecutive patients receiving a CRT-capable defibrillator in 2004 at a tertiary care center for standard indications were studied. Clinical data and medications upon hospital discharge were recorded. Patients were followed for endpoints of death or transplantation. Results Of 177 patients receiving a CRT device, 129 (73%) received BB therapy (group 1). Of the 48 patients not on BBs (group 2), relative contraindications were documented in 21 (allergy in 3, hypotension or inotrope-dependent HF in 4, chronic obstructive pulmonary disease [COPD] in 6, and amiodarone therapy in 8). The remaining 27 patients (group 3) did not receive BB therapy despite absence of documented justification. Compared to group 1, group 3 patients were similar in terms of clinical characteristics and angiotensin-converting enzyme inhibitor (ACEI) use, but were less likely to be on statin therapy. Patients were followed for a mean of 19.9 ± 9.2 mo. After adjusting for age, QRS duration, creatinine, left ventricular ejection fraction (LVEF), statin use, and presence of ischemic HF etiology, patients not receiving BB therapy in the absence of contraindication had increased risk of death or transplantation (odds ratio [OR]: 3.1, p = 0.043). Conclusions Absence of BB therapy appears to be independently associated with poor outcome in CRT recipients. These results suggest that a crucial component of OPT may be underutilized in a population of HF patients receiving CRT. Copyright © 2009 Wiley Periodicals, Inc. [source]