Influence of stentless versus stented valves on ventricular remodeling assessed at 6 months by magnetic resonance imaging and long-term follow-up.

BACKGROUND: To compare the effect of stented versus stentless bioprostheses on left ventricular remodeling and assess their impact on long-term survival. METHODS: From January 2002 to December 2009, 62 severe aortic stenosis patients without coronary artery disease were randomized for bioprosthetic aortic valve replacement. After randomization, a cross-over was possible based on intraoperative data. Ventricular remodeling was studied by cardiovascular magnetic resonance imaging six months after surgery. Long-term survival was assessed by telephone survey. RESULTS: Thirty-five patients received a porcine Mosaïc® Medtronic bioprosthesis (Stented Group; Medtronic, Minneapolis, MN, USA) inserted using the usual supra-annular technique and 27 received a porcine Freestyle® Medtronic bioprosthesis (Stentless Group) inserted in the subcoronary position. Mean age was 75±3 and 73±4 years in the stentless and stented group, respectively. Nine patients who should have been implanted with a stentless bioprosthesis received a stented bioprosthesis for anatomical reasons. At 6 months, the left ventricular mass (LVM) decreased significantly in both groups (Stentless Group: 214.6±56.1g and 156.3±23g and Stented Group: 237±75.7g and 181±53.3g, respectively after surgery and at 6 months), this decrease was significantly greater in the stentless group (p=0.026). Reserve and coronary flow were increased in both groups at 6 months. Mean follow-up duration was 6.6±3.0 years and 7.2±4.0 years in the stentless and stented group, respectively. The 5-year actuarial survival was 87.5±11.7% and 82.5±17.1% for the stentless and stented group, respectively (p=0.81). CONCLUSION: Porcine stentless prosthesis results in a better LVM regression than a stented valve at 6 months without changing the long-term survival.

Non-physiological increase of AV conduction time in sinus disease patients programmed in AAIR-based pacing mode.

PURPOSE: The EVOCAV(DS) trial aimed to quantify the paradoxal atrioventricular (AV) conduction time lengthening in sinus node (SD) patients (pts) paced in AAIR-based pacing mode. METHODS: SD pts, implanted with dual-chamber pacemaker programmed in AAIR-based pacing mode, were randomized in two arms for a 1-month period: the low atrial pacing (LAP; basic rate at 60 bpm, dual sensor with minimal slope) and the high atrial pacing (HAP; basic rate at 70 bpm, dual sensor with optimized slope, overdrive pacing) arm. At 1 month, crossover was performed for an additional 1-month period. AV conduction time, AV block occurrence and AV conduction time adaptation during exercise were ascertained from device memories at each follow-up. RESULTS: Seventy-nine pts participated to the analysis (75 ± 8 years; 32 male; PR = 184 ± 38 ms; bundle branch block n = 12; AF history n = 36; antiarrhythmic treatment n = 53; beta-blockers n = 27; class III/Ic n = 18; both n = 8). The mean AV conduction time was significantly greater during the HAP (275 ± 51 ms) vs. LAP (263 ± 49 ms) period (p < 0.0001). Class III/Ic drugs were the only predictors of this abnormal behaviour. Degree II/III AV blocks occurred in 49 % of pts in the HAP vs. 19 % in the LAP period (p < 0.0001). Fifty-two patients (66 %) presented a lengthening of AV conduction time during exercise. CONCLUSION: AAIR-based pacing in SD pts may induce a significant lengthening of pts' AV conduction time, including frequent abnormal adaptation of AV conduction time during exercise.

A randomized study of defibrillator lead implantations in the right ventricular mid-septum versus the apex: the SEPTAL study.

INTRODUCTION: The study was designed to evaluate the feasibility and performance of right ventricular (RV) mid-septal versus apical implantable defibrillator (ICD) lead placement. METHODS AND RESULTS: SEPTAL is a randomized, noninferiority trial, which randomly assigned patients to implantation of ICD leads in the RV mid-septum versus apex, with a primary objective of comparing the implant success rate of implant at each site, based on strict electrical predefined criteria. We also compared the (1) pacing lead characteristics, (2) rates of appropriate and inappropriate ICD therapies, and (3) all-cause mortality between the 2 sites at 1 year. The trial enrolled 215 patients (mean age = 59.7 ± 12.4 years, mean LVEF = 34.0 ± 14.2%, 84.2% men), of whom 148 (68.8%) presented with ischemic heart disease. The ICD indication was primary prevention in 117 patients (54.4%). The lead was successfully implanted in 96/107 patients (89.7%) assigned to the RV mid-septum, and in 99/108 (91.7%) assigned to the apex (ns). The 1-year rate of lead-related adverse events was similar in both groups. A total of 8 first inappropriate ICD therapies (7.9%) were delivered in the RV mid-septal group, versus 8 (7.8%) in the apical group (ns), while first appropriate therapies were delivered to 22 (21.4%) and 24 patients (23.8%), respectively (ns). All-cause mortality was 7.9% in the RV mid-septal versus 2.9% in the RV apical group (ns). CONCLUSION: This study confirmed the technical feasibility and noninferior performance of ICD leads implanted in the RV mid-septum versus the apex.

Relationship between amplitude and timing of heart sounds and endocardial acceleration.

OBJECTIVE: To study the correlation between heart sounds and peak endocardial acceleration (PEA) amplitudes and timings, by modulation of paced atrioventricular (AV) delay in recipients of dual chamber pacemakers. METHODS: Ten recipients of dual chamber pacemakers implanted for high-degree AV block were studied. Endocardial acceleration (EA) and phonocardiographic and electrocardiographic signals were recorded during performance of an AV delay scan in VDD and DDD modes. RESULTS: First PEA (PEA I) and first heart sound (S1) changed similarly with the AV delay. A close intrapatient correlation was observed between S1 and PEA I amplitudes in all patients (P < 0.0001). The interpatient normalized PEA I to S1 amplitudes correlation was r = 0.89 (P < 0.0001) in DDD mode, and r = 0.81 (P < 0.0001) in VDD mode. The mean cycle-by-cycle PEA I to S1 delay was -4.3 +/- 22 ms and second PEA (PEA II) to second heart sound (S2) delay was -7.7 +/- 15 ms. CONCLUSIONS: A close correlation was observed between PEA I and S1 amplitudes and timings, and between PEA II and S2 timings. These observations support the hypothesis that PEA and heart sounds are manifestations of the same phenomena. EA might be a useful tool to monitor cardiac function.