The aim of this study was to assess the association between maximum daily atrial fibrillation (AF) burden and risk of ischaemic stroke.
Cardiac implanted electronic devices (CIEDs) enhance detection ...of AF, providing a comprehensive measure of AF burden.
A pooled analysis of individual patient data from five prospective studies was performed. Patients without permanent AF, previously implanted with CIEDs, were included if they had at least 3 months of follow-up. A total of 10 016 patients (median age 70 years) met these criteria. The risk of ischaemic stroke associated with pre-specified cut-off points of AF burden (5 min, 1, 6, 12, and 23 h, respectively) was assessed.
During a median follow-up of 24 months, 43% of 10 016 patients experienced at least 1 day with at least 5 min of AF burden and for them the median time to the maximum AF burden was 6 months (inter-quartile range: 1.3-14). A Cox regression analysis adjusted for the CHADS2 score and anticoagulants at baseline demonstrated that AF burden was an independent predictor of ischaemic stroke. Among the thresholds of AF burden that we evaluated, 1 h was associated with the highest hazard ratio (HR) for ischaemic stroke, i.e. 2.11 (95% CI: 1.22-3.64, P = 0.008).
Device-detected AF burden is associated with an increased risk of ischaemic stroke in a relatively unselected population of CIEDs patients. This finding may add to the basis for timely and clinically appropriate decision-making on anticoagulation treatment.
(1) discussed their results in the context of MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial Reduce Inappropriate Therapy) (2) data assessing whether the 2 results are ...contradicting and concluded that "combining the results of the 2 studies, one could conclude that unnecessary ATP antitachycardia pacing may increase mortality, while unnecessary shocks for sinus tachycardia, SVT supraventricular tachycardia, or noise/artifact/oversensing does not appear to affect long-term survival."
The risk of permanent pacemaker implantation (PPI) after cardiac valve replacement surgery is thought to be highest in the postoperative period. Long-term risks are uncertain.
The purpose of this ...study was to determine rates and timing of PPI after cardiac valve replacement surgery.
We compared PPI rates of patients undergoing aortic valve replacement (AVR; n = 111,674), mitral valve replacement (MVR; n = 18,402), AVR + MVR (n = 5166), AVR + MVR + tricuspid valve replacement (TVR; n = 114), or coronary artery bypass surgery (CABG) without valve replacement (n = 249,742).
Over a period of 14 years (median 3.9 years; interquartile range 1.1-7.4 years), cumulative PPI rates were 3.07-7.6 times higher (P < .001 for all) than after CABG, depending on the number of valves replaced. PPI risks after AVR were higher that those after MVR (hazard ratio HR 1.22; 95% confidence interval CI 1.16-1.28), AVR + MVR (HR 1.52; 95% CI 1.40-1.65), and AVR + MVR + TVR (HR 2.22; 95% CI 1.40-3.53), independent of known confounders. Cumulative PPI hazard rates from the postoperative period to 10 years after surgery increased after AVR (4.22%-14.4%), MVR (4.38%-15.6%), AVR + MVR (5.59%-18.3%), and AVR + MVR + TVR (7.89%-25.9%) (P < .001 for all). Age, male sex, emergency admission, and preexisting diabetes mellitus, renal impairment, and heart failure were independent predictors of PPI (P < .001 for all).
Valve replacement surgery was associated with a long-term risk of PPI. This was particularly high after dual and triple valve replacements. Age, male sex, emergency admission, and preexisting diabetes mellitus, heart failure, and renal impairment were independent predictors of PPI.
Data from randomized trials have suggested a modest or no effect of conventional cardiac resynchronization therapy (convCRT) on the incidence of atrial fibrillation (AF). AdaptivCRT (aCRT, Medtronic, ...Mounds View, MN) is a recently described algorithm for synchronized left ventricular (LV) pacing and continuous optimization of cardiac resynchronization therapy (CRT).
We compared the long-term effects of aCRT with convCRT pacing on the incidence of AF.
The Adaptive CRT trial randomized CRT-defibrillator (CRT-D)–indicated patients (2:1) to receive either aCRT or convCRT pacing. The aCRT algorithm evaluates intrinsic conduction every minute, providing LV-only pacing during normal atrioventricular (AV) conduction and AV and ventriculoventricular timing adjustments during prolonged AV conduction. The primary outcome of this subanalysis was an episode of AF >48 consecutive hours as detected by device diagnostics.
Over a follow-up period with a mean and standard deviation of 20.2 ± 5.9 months, 8.7% of patients with aCRT and 16.2% with convCRT experienced the primary outcome (hazard ratio HR = 0.54; 95% confidence interval CI = 0.31–0.93; P = .03). In patients with prolonged baseline AV, the incidence of the primary outcome was 12.8% in patients randomized to aCRT compared with 27.4% in convCRT patients (HR = 0.45; 95% CI = 0.24–0.85; P = .01). Also, patients with AF episodes adjudicated as clinical adverse events were less common with aCRT (4.3%) than with convCRT (12.7%) (HR = 0.39; 95% CI = 0.19–0.79; P = .01).
Patients receiving aCRT had a reduced risk of AF compared with those receiving convCRT. Most of the reduction in AF occurred in subgroups with prolonged AV conduction at baseline and with significant left atrial reverse remodeling.
Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP ...synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control).
To examine whether synchronized LVP (sLVP) resulted in better clinical outcomes.
First, stratification by percent sLVP (%sLVP) and multivariate Cox proportional hazards model was used to assess the relationship between %sLVP and clinical outcomes. Second, outcomes were compared between patients in the aCRT arm (n = 318) and control patients (n = 160) stratified by intrinsic AV interval at randomization.
In the aCRT arm, %sLVP ≥50% (n = 142) was independently associated with a decreased risk of death or heart failure hospitalization (hazard ratio 0.49; 95% confidence interval 0.28-0.85; P = .012) compared with %sLVP <50% (n = 172). A greater proportion of patients with %sLVP ≥50% improved in Packer's clinical composite score at 6-month (82% vs. 68%; P = .002) and 12-month (80% vs. 62%; P = .0006) follow-ups compared to controls. In the subgroup with normal AV (n = 241), there was a lower risk of death or heart failure hospitalization (hazard ratio 0.52; 95% confidence interval 0.27-0.98; P = .044) with the aCRT algorithm. A greater proportion of patients in the aCRT arm improved in the clinical composite score at 6-month (81% vs. 69%; P = .041) and 12-month (77% vs. 66%; P = .076) follow-ups compared to controls.
Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.
Objectives The purpose of this analysis was to evaluate the correlation between atrial tachycardia (AT) or atrial fibrillation (AF) and clinical outcomes in heart failure (HF) patients implanted with ...a cardiac resynchronization therapy defibrillator (CRT-D). Background In HF patients, AT and AF have high prevalence and are associated with compromised hemodynamic function. Methods Forty-four Italian cardiological centers followed up 1,193 patients who received a CRT-D according to current guidelines for advanced HF, New York Heart Association functional class ≥II, left ventricular ejection fraction ≤35%, and QRS complex ≥120 ms. All patients were in sinus rhythm at implant. Results During a median follow-up period of 13 months, AT/AF >10 min occurred in 361 of 1,193 (30%) patients. The composite end point (deaths or HF hospitalizations) occurred in 174 of 1,193 (14.6%). Multivariate time-dependent Cox regression analyses showed that composite end point risk was higher among patients with device-detected AT/AF (hazard ratio HR: 2.16, p = 0.032), New York Heart Association functional class III or IV compared with II (HR: 2.09, p = 0.002), and absence of beta-blockers (HR: 1.36, p = 0.036). Furthermore, the composite end point risk was inversely associated with left ventricular ejection fraction (HR: 1.04, p = 0.045), increasing by a factor of 4% for each 1% decrease in left ventricular ejection fraction. Conclusions In HF patients with CRT-D, device-detected AT/AF is associated with a worse prognosis. Continuous device diagnostics monitoring and Web-based alerts may inform the physician of AT/AF occurrences and identify patients at risk of cardiac deterioration or patients with suboptimal rate or rhythm control. (Italian ClinicalService Project; NCT01007474 )
Cardiac resynchronization therapy (CRT) is a device-based, nonpharmacologic approach that has shown to improve the outcome in patients with heart failure in terms of mortality and morbidity ...reduction. Large randomized trials have virtually enrolled patients in New York Heart Association class III-IV, with reduced left ventricular ejection fraction, with evidence of electrical dyssynchrony, and receiving optimal medical therapy and who were in sinus rhythm. Guidelines remain imprecise as to defining differentiated approaches according to the forms of atrial fibrillation other than permanent. These recommendations remain unsupported by evidence derived from randomized controlled trials, which are much needed.
Objectives The purpose of this study is to determine whether, in patients with atrial fibrillation (AF) undergoing cardiac resynchronization therapy (CRT), atrioventricular junction ablation (AVJA) ...is associated with a better outcome than treatment with rate-slowing drugs. Background Different trials have demonstrated that CRT is effective in treating heart failure (HF) patients who are in sinus rhythm (SR). No trials have addressed whether CRT confers similar benefits on AF patients, with or without AVJA. Methods The clinical outcomes of CRT for patients with permanent AF undergoing CRT combined with either AVJA (n = 443) or rate-slowing drugs (n = 895) were compared with those of SR patients (n = 6,046). Results Median follow-up was 37 months. Total mortality (6.8 vs. 6.1 per 100 person-years) and cardiac mortality (4.2 vs. 4.0) were similar for patients with AF+AVJA and patients in SR (both p = NS). In contrast, the AF+drugs group had a higher total and cardiac mortality than the SR group and the AF+AVJA group (11.3 and 8.1, respectively; p < 0.001). On multivariable analysis, AF+AVJA had total mortality (hazard ratio HR: 0.93, 95% confidence interval CI: 0.74 to 1.67) and cardiac mortality (HR: 0.88, 95% CI: 0.66 to 1.17) similar to that of the SR group, independent of known confounders. The AF+drugs group, however, had a higher total mortality (HR: 1.52, 95% CI: 1.26 to 1.82) and cardiac mortality (HR: 1.57, 95% CI: 1.27 to 1.94) than both the SR group and the AF+AVJA group (both p < 0.001). Conclusions Long-term survival after CRT among patients with AF+AVJA is similar to that observed among patients in SR. Mortality is higher for AF patients treated with rate-slowing drugs.
Background Women are underrepresented in cardiac resynchronization therapy (CRT) trials. Some studies suggest that women fare better than men after CRT. We sought to explore clinical outcomes in ...women and men undergoing CRT-defibrillation or CRT-pacing in real-world clinical practice. Methods and Results A national database (Hospital Episode Statistics for England) was used to quantify clinical outcomes in 43 730 patients (women: 10 890 24.9%; men: 32 840 75.1%) undergoing CRT over 7.6 years, (median follow-up 2.2 years, interquartile range, 1-4 years). In analysis of the total population, the primary end point of total mortality (adjusted hazard ratio aHR, 0.73; 95% CI, 0.69-0.76) and the secondary end point of total mortality or heart failure hospitalization (aHR, 0.79, 95% CI 0.75-0.82) were lower in women, independent of known confounders. Total mortality (aHR, 0.73; 95% CI, 0.70-0.76) and total mortality or heart failure hospitalization (aHR, 0.79; 95% CI, 0.75-0.82) were lower for CRT-defibrillation than for CRT-pacing. In analyses of patients with (aHR, 0.89; 95% CI, 0.80-0.98) or without (aHR, 0.70; 95% CI, 0.66-0.73) a myocardial infarction, women had a lower total mortality. In sex-specific analyses, total mortality was lower after CRT-defibrillation in women (aHR, 0.83;
=0.013) and men (aHR, 0.69;
<0.001). Conclusions Compared with men, women lived longer and were less likely to be hospitalized for heart failure after CRT. In both sexes, CRT-defibrillation was superior to CRT-pacing with respect to survival and heart failure hospitalization. The longest survival after CRT was observed in women without a history of myocardial infarction.
Background The magnitude of benefit of cardiac resynchronization therapy (CRT) varies significantly among its recipients; approximately 30% of CRT patients do not report clinical improvement. ...Optimization of CRT pacing parameters can further improve cardiac function, both acutely and chronically. Echocardiographic optimization is used in clinical practice, but it is time and resource consuming. In addition, optimal settings at rest may change later with activity or cardiac remodeling. The adaptive CRT (aCRT) algorithm was designed to provide automatic ambulatory adjustment of CRT pacing configuration (left ventricular or biventricular pacing) and device delays based on periodic measurement of electrical conduction intervals. Methods The aCRT algorithm is currently undergoing evaluation in a prospective, randomized, double-blinded, worldwide clinical trial. The trial enrolled 522 patients, who satisfied standard clinical indications for a CRT device. Within 2 weeks after the implant, the patients were randomized to aCRT versus echo-optimized biventricular pacing (Echo) settings in 2:1 ratio and followed up at 1-, 3-, 6-, and 12-month postrandomization. The noninferiority primary trial objectives at 6-month postrandomization are to demonstrate that ( a ) the percentage of aCRT patients who improved in their clinical composite score is at least as high as the percentage of Echo patients; ( b ) cardiac performance as assessed by echocardiography is similar when using aCRT settings versus echo-optimized settings; and ( c ) aCRT does not result in inappropriate device settings. First and last patient enrollments occurred in November 2009 and December 2010, respectively. Conclusions The safety and efficacy of the aCRT algorithm will be evaluated in this ongoing clinical trial.
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