Device-detected atrial sensing amplitudes as a marker of increased risk for new onset and progression of atrial high-rate episodes.

BACKGROUND: Atrial high-rate episodes (AHREs) are frequent in patients with cardiac implantable electronic devices. A decrease in device-detected P-wave amplitude may be an indicator of periods of increased risk of AHRE. OBJECTIVE: The objective of this study was to assess the association between P-wave amplitude and AHRE incidence. METHODS: Remote monitoring data from 2579 patients with no history of atrial fibrillation (23% pacemakers and 77% implantable cardioverter-defibrillators, of which 40% provided cardiac resynchronization therapy) were used to calculate the mean P-wave amplitude during 1 month after implantation. The association with AHRE incidence according to 4 strata of daily burden duration (≥15 minutes, ≥6 hours, ≥24 hours, ≥7 days) was investigated by adjusting the hazard ratio with the CHA2DS2-VASc score. RESULTS: The adjusted hazard ratio for 1-mV lower mean P-wave amplitude during the first month increased from 1.10 (95% confidence interval [CI], 1.05-1.15; P < .001) to 1.18 (CI, 1.09-1.28; P < .001) with AHRE duration strata from ≥15 minutes to ≥7 days independent of the CHA2DS2-VASc score. Of 871 patients with AHREs, those with 1-month P-wave amplitude <2.45 mV had an adjusted hazard ratio of 1.51 (CI, 1.19-1.91; P = .001) for progression of AHREs from ≥15 minutes to ≥7 days compared with those with 1-month P-wave amplitude ≥2.45 mV. Device-detected P-wave amplitudes decreased linearly during the 1 year before the first AHRE by 7.3% (CI, 5.1%-9.5%; P < .001 vs patients without AHRE). CONCLUSION: Device-detected P-wave amplitudes <2.45 mV were associated with an increased risk of AHRE onset and progression to persistent forms of AHRE independent of the patient's risk profile.

Ventricular Arrhythmias and Implantable Cardioverter-Defibrillator Therapy in Women: A Propensity Score-Matched Analysis.

BACKGROUND: Causes of sex differences in incidence of sustained ventricular arrhythmias (SVAs) are poorly understood. OBJECTIVES: This study aims to investigate sex-specific risk of SVAs and device therapies by balancing sex groups in relation to several baseline characteristics with the propensity score (PS). METHODS: We used a large remote monitoring dataset from implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds). Study endpoints were time to the first appropriate SVA, time to the first device therapy for SVA, and time to the first ICD shock. Results were compared between females and a PS-matched male subgroup. RESULTS: In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. After selecting 488 men PS-matched for 19 variables relative to baseline demographics, implant indications, principal comorbidities, and concomitant therapy, yet the SVA rate at the 2.1-year median follow-up was significantly lower in women than in man (adjusted HR: 0.65; 95% CI: 0.51-0.81; P < 0.001). Women also showed a reduced risk of any device therapy (HR: 0.59; 95% CI: 0.45-0.76; P < 0.001) and shocks (HR: 0.66; 95% CI: 0.47-0.94; P = 0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR: 0.78; 95% CI: 0.55-1.09; P = 0.14) nor in those with an ejection fraction <30% (HR: 0.80; 95% CI: 0.52-1.23; P = 0.31). CONCLUSIONS: After matching demographics, indications, principal comorbidities, and concomitant therapy, women still exhibited a lower SVA risk profile than men, except in the subgroups of CRT-D or/and ejection fraction <30%.

"Shift and cover technique": conservative management of complications for the rescue of S-ICD subcutaneous implantable defibrillator systems.

BACKGROUND: The risk of complications has been shown to be lower with subcutaneous implantable defibrillator (S-ICD) than with conventional ICDs. Given the low frequency of complications, experience of how to manage them is limited. In this paper, we describe generator- and lead-related complications recorded in a series of S-ICD patients, and we propose our conservative approach to managing them. METHODS: The study cohort consisted of S-ICD patients who were referred to our institution owing to generator- or lead-related complications requiring surgical intervention. With our "shift and cover" approach, the system component involved is moved from its original position to an alternative, more protected location. In the case of the generator, this involves moving it to an intermuscular pocket. In the case of infections at the parasternal scar, the electrode sleeve is moved away from its original location, stitched, and then covered with the muscular fascia. RESULTS: Fourteen S-ICD patients were referred to our institution owing to system-related complications. Complications involved the generator in 7 cases (deep pocket infections with erosion, extrusion, or pain), the lead in 5 cases (parasternal infections at the xyphoid incision site), and both the generator and the lead in 2 cases. Complications were managed without completely removing the device and resolved in a single surgical session with no intraoperative complications. During defibrillation testing, the first shock at 65 J was effective in all patients. The shock impedance after revision was significantly lower than that measured during first implantation (59 ± 10 Ohm versus 86 ± 24 Ohm, P = 0.013). In all cases, the cosmetic result was satisfactory. No complications or recurrent infections were reported at the 12-month follow-up visit. CONCLUSIONS: The proposed conservative approach was successful in managing S-ICD complications. The revision procedure allowed to optimize the system configuration in terms of the defibrillation vector, resulting in lower shock impedance values and better device positioning.

Active fixation of bipolar left ventricular lead through a persistent left superior vena cava.

A left superior vena cava persistence was found in a 61 year-old patient affected by dilated and hypokinetic cardiopathy with severe dysfunction of the left ventricle (left ventricular ejection fraction of 32%) and valvular disease. After a negative coronary angiography, he was implanted with a cardiac resynchronization therapy with defibrillation function device (CRT-D). The present case describes the successful implantation of a biventricular defibrillator in this challenging congenital abnormality of cardiac venous system.

Circadian periodicity affects the type of ventricular arrhythmias and efficacy of implantable defibrillator therapies.

INTRODUCTION: Factors influencing malignant arrhythmia onset are not fully understood. We explored the circadian periodicity of ventricular arrhythmias (VAs) in patients with implantable cardioverter and cardiac resynchronization defibrillators (ICD/CRT-D). METHODS: Time, morphology (monomorphic/polymorphic), and mode of termination (anti-tachycardia pacing [ATP] or shock) of VAs stored in a database of remote monitoring data were adjudicated. Episodes were grouped in six 4-h timeslots from 00:00 to 24:00. Circadian distributions and adjusted marginal odds ratios (ORs), with 95% confidence interval (CI), were analyzed using mixed-effect models and logit generalized estimating equations, respectively, to account for within-subject correlation of multiple episodes. RESULTS: Among 1303 VA episodes from 446 patients (63% ICD and 37% CRT-D), 120 (9%) self-extinguished, and 842 (65%) were terminated by ATP, 343 (26%) by shock. VAs clustered from 08:00 to 16:00 with 44% of episodes, as compared with 22% from 00:00 to 08:00 (p < .001) and 34% from 16:00 to 24:00 (p = .005). Episodes were more likely to be polymorphic at night with an adjusted marginal OR of 1.66 (CI, 1.15-2.40; p = .007) at 00:00-04:00 versus other timeslots. Episodes were less likely to be terminated by ATP in the 00:00-04:00 (success-to-failure ratio, 0.67; CI, 0.46-0.98; p = .039) and 08:00-12:00 (0.70; CI, 0.51-0.96; p = .02) timeslots, and most likely to be terminated by ATP between 12:00 and 16:00 (success-to-failure ratio 1.42; CI, 1.06-1.91; p = .02). CONCLUSION: VAs did not distribute uniformly over the 24 h, with a majority of episodes occurring from 08:00 to 16:00. Nocturnal episodes were more likely to be polymorphic. The efficacy of ATP depended on the time of delivery.

Does the Age Affect the Outcomes of Cardiac Resynchronization Therapy in Elderly Patients?

BACKGROUND: More and more heart failure (HF) patients aged ≥ 75 years undergo cardiac resynchronization therapy (CRT) device implantation, however the data regarding the outcomes and their predictors are scant. We investigated the mid- to long-term outcomes and their predictors in CRT patients aged ≥ 75 years. METHODS: Patients in the Cardiac Resynchronization Therapy Modular (CRT MORE) Registry were divided into three age-groups: <65 (group A), 65-74 (group B) and ≥75 years (group C). Mortality, hospitalization, and composite event rate were evaluated at 1 year and during long-term follow-up. RESULTS: Patients (n = 934) were distributed as follows: group A 242; group B 347; group C 345. On 12-month follow-up examination, 63% of patients ≥ 75 years displayed a positive clinical response. Mortality was significantly higher in patients ≥ 75 years than in the other two groups, although the rate of hospitalizations for HF worsening was similar to that of patients aged 65-74 (7 vs. 9.5%, respectively; p = 0.15). Independent predictors of death and of negative clinical response were age >80 years, chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD). Over long-term follow-up (1020 days (IQR 680-1362)) mortality was higher in patients ≥ 75 years than in the other two groups. Hospitalization and composite event rates were similar in patients ≥ 75 years and those aged 65-74 (9 vs. 11.8%; p = 0.26, and 26.7 vs. 20.5%; p = 0.06). CONCLUSION: Positive clinical response and hospitalization rates do not differ between CRT recipients ≥ 75 years and those aged 65-74. However, age > 80 years, COPD and CKD are predictors of worse outcomes.

Cryoballoon or radiofrequency ablation? Alternating technique for repeat procedures in patients with atrial fibrillation.

BACKGROUND: Which technique is better for repeat ablation in patients with atrial fibrillation (AF) remains unclear. The aim of the study was to compare long-term efficacy of repeat ablation using the alternative technique for the first redo ablation procedure: (a) cryoballoon (CB) re-ablation after a failed index pulmonary vein isolation (PVI) with radiofrequency (RF) ablation, RF-then-CB group or (b) RF repeat ablation following a failed CB ablation, CB-then-RF group. METHODS: Within the 1STOP Italian Project, consecutive patients undergoing repeat ablation with a different technique from the index procedure were included. RESULTS: We studied 474 patients, 349 in RF-then-CB and 125 in CB-then-RF group. Less women (21% vs 30%; P = .041), more persistent AF (33% vs 22%; P = .015), longer duration of AF (60 vs 31 months; P < .001), and more hypertension (50% vs 36%; P = .007) were observed in the RF-then-CB cohort as compared with the CB-then-RF group. The number of reconnected PVs was 3.7 ± 0.7 and 1.4 + 1.3 in RF-then-CB and CB-then-RF group, respectively (P < .001). During the follow-up, significantly less AF recurrence occurred in the CB-then-RF group (22% vs 8%, HR = 0.46; 95% CI: 0.24-0.92; P = .025). Cohort designation was the only independent predictor of AF recurrence. CONCLUSION: Alternation of energy source for repeat ablation was safe and effective, regardless the energy used first. However, patients initially treated with CB PVI undergoing repeat ablation with RF current had less AF recurrence at long-term follow-up as compared with those originally treated by RF ablation receiving a CB repeat ablation.

Epicardial left ventricular lead implantation in cardiac resynchronization therapy patients via a video-assisted thoracoscopic technique: Long-term outcome.

BACKGROUND: Epicardial placement of the left ventricular (LV) lead via a video-assisted thoracoscopic (VAT) approach is an alternative to the standard transvenous technique. HYPOTHESIS: Long-term safety and efficacy of VAT and transvenous LV lead implantation are comparable. To test it, we reviewed our experience and we compared the outcomes of patients who underwent implantation with the two techniques. METHODS: The VAT procedure is performed under general anesthesia, with oro-tracheal intubation and right-sided ventilation, and requires two 5 mm and one 15 mm thoracoscopic ports. After pericardiotomy at the spot of the epicardial target area, pacing measurements are taken and a spiral screw electrode is anchored at the final pacing site. The electrode is then tunneled to the pectoral pocket and connected to the device. RESULTS: 105 patients were referred to our center for epicardial LV lead implantation. After pre-operative assessment, 5 patients were excluded because of concomitant conditions precluding surgery. The remaining 100 underwent the procedure. LV lead implantation was successful in all patients (median pacing threshold 0.8 ± 0.5 V, no phrenic nerve stimulation) and cardiac resynchronization therapy was established in all but one patient. The median procedure time was 75 min. During a median follow-up of 24 months, there were no differences in terms of death, cardiovascular hospitalizations or device-related complications vs the group of 100 patients who had undergone transvenous implantation. Patients of both groups displayed similar improvements in terms of ventricular reverse remodeling and functional status. CONCLUSIONS: Our VAT approach proved safe and effective, and is a viable alternative in the case of failed transvenous LV implantation.

Is the time between first diagnosis of paroxysmal atrial fibrillation and cryoballoon ablation a predictor of efficacy?

AIMS: Cryoablation is an indicated therapy for the treatment of recurrent atrial fibrillation through pulmonary vein isolation; however, the optimal time between first diagnosis of atrial fibrillation and cryoablation is still unknown. We aimed to assess the clinical efficacy and safety of early versus later treatment of patients with paroxysmal atrial fibrillation by cryoablation. METHODS: Five hundred and ten patients underwent atrial fibrillation cryoablation and were prospectively followed for at least 6 months in 43 Italian cardiology centers. The population was divided into two groups according to the time since the first diagnosis of atrial fibrillation until the index cryoablation procedure. An early-treatment group had an elapsed time of 15 months or less from atrial fibrillation diagnosis until cryoablation, and the late-treatment group had an elapsed time of greater than 15 months. During the evaluation, clinical efficacy was defined as atrial fibrillation recurrence outside a landmark 90-day blanking period, and safety was defined as the reporting of all procedure-related complications. RESULTS: In the total cohort, cryoablation was performed after a median of 36 months from the point of the patient diagnosis with drug refractory symptomatic recurrent atrial fibrillation. The early-treatment group was composed of 130 (25%) patients, whereas the late-treatment group had 380 (75%) patients. Both cohorts had similar baseline clinical characteristics. Of 510 patients, 22 had a complication related to the procedure with no difference between the two groups. Multivariable analysis showed that the risk of atrial fibrillation recurrence was significantly higher in the late-treatment group (hazard ratio: 1.77; 95% confidence interval 1.00-3.13) CONCLUSION: In our multicenter observational examination, cryoablation was well tolerated and effective in the treatment of patients with drug refractory symptomatic paroxysmal atrial fibrillation. Reducing the time between diagnosis and ablation brought about a treatment that had a lower risk of atrial fibrillation recurrence with no change in safety.(Italian ClinicalService Project: NCT01007474).

Predictors of Zero X-Ray Ablation for Supraventricular Tachycardias in a Nationwide Multicenter Experience.

BACKGROUND: This multicenter, prospective study evaluated the determinants of zero-fluoroscopy (ZFL) ablation of supraventricular tachycardias. METHODS AND RESULTS: Four hundred thirty patients (215 male, 55.4±22.1 years) with indication to electrophysiological study or ablation of supraventricular tachycardias were enrolled. All participating physicians agreed to follow the as low as reasonably achievable policy. A procedure was defined as ZFL when no fluoroscopy was used. The total fluoroscopy time inversely correlated to the number of procedures previously performed by each operator since study start (r=-0.112; P=0.02). Two hundred eighty-nine procedures (67.2%) were ZFL; multivariable analysis identified as predictors of ZFL: procedure after the 30th for each operator, compared with procedures up to the ninth (P=0.011; hazard ratio, 3.49; 95% confidence interval [CI], 1.79-6.80); the type of arrhythmia (P=0.031; electrophysiological study and atrioventricular nodal reentry tachycardia ablation having the highest probability of ZFL; hazard ratio, 6.87; 95% CI, 2.08-22.7 and hazard ratio, 2.02; 95% CI, 1.04-3.91, respectively); the operator's (P=0.002) and patient's age (P=0.009). Among operators, achievement of ZFL varied from 0% to 100%; 8 (22.8%) operators achieved ZFL in <25% of their procedures; 17 (48.6%) operators achieved ZFL in >75% of their procedures. The probability of ZFL increased by 2.8% (hazard ratio, 0.98; 95% CI, 0.97-0.99) as patient's age decreased by 1 year. Acute procedural success was obtained in all cases. CONCLUSIONS: The use of 3-dimensional mapping system completely avoided the use of fluoroscopy in most cases, with very low fluoroscopy time in the remaining and high safety and effectiveness profiles. Achievement of ZFL was predicted by the type of arrhythmia, operator's experience, and patient's age.

Adherence to 2016 European Society of Cardiology guidelines predicts outcome in a large real-world population of heart failure patients requiring cardiac resynchronization therapy.

BACKGROUND: Professional guidelines are based on the best available evidence. However, patients treated in clinical practice may differ from those included in reference trials. OBJECTIVE: The aim of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) in a large population of patients implanted with a CRT device stratified in accordance with the 2016 European heart failure (HF) guidelines. METHODS: We collected data on 930 consecutive patients from the Cardiac Resynchronization Therapy MOdular REgistry. The primary end point was a composite of death and HF hospitalization. RESULTS: Five hundred sixty-three (60.5%) patients met class I indications, 145 (15.6%) class IIa, 108 (11.6%) class IIb, and 114 (12.3%) class III. After a median follow-up of 1001 days, 120 (14.7%) patients who had an indication to CRT had died and 71 (8.7%) had been hospitalized for HF. The time to the end point was longer in patients with a class I indication (hazard ratio 0.55; 95% confidence interval 0.39-0.76; P = .0001). After 12 months, left ventricular (LV) end-systolic volume had decreased by ≥15% in 61.5% (320/520) of patients whereas in 57.5% (389/676) of patients the absolute LV ejection fraction improvement was ≥5%. Adherence to class I was also associated with an absolute LV ejection fraction increase of >5% (P = .0142) and an LV end-systolic volume decrease of ≥15% (P = .0055). CONCLUSION: In our population, ∼60% of patients underwent implantation according to the 2016 European HF guidelines class I indication. Adherence to class I was associated with a lower death and HF hospitalization rates and better LV reverse remodeling.

Maximization of interventricular conduction time by means of quadripolar leads for cardiac resynchronization therapy.

PURPOSE: Identifying the left ventricular (LV) site associated with the maximum spontaneous interventricular conduction time (right ventricle (RV)-to-LV interval) has proved to be an effective strategy for optimal LV pacing site selection in cardiac resynchronization therapy (CRT). The aim of our study was to determine whether quadripolar LV lead technology allows RV-to-LV interval maximization. METHODS: We enrolled 108 patients undergoing implantation of a CRT system using an LV quadripolar lead and 114 patients who received a bipolar lead. On implantation, the RV-to-LV interval was measured for the dipole of the bipolar leads and for each electrode of the LV lead (tip, ring 2, ring 3, ring 4). RESULTS: In the quadripolar group, the mean RV-to-LV interval ranged from 90 ± 33 ms (tip) to 94 ± 32 ms (R4) (p > 0.05 for all comparisons). In 55 (51%) patients, the RV-to-LV interval was > 80 ms at all electrodes, while in 27 (25%) patients, no electrodes were associated with an RV-to-LV interval > 80 ms. At least one LV pacing electrode was associated with an RV-to-LV interval > 80 ms in 62 (70%) patients with a short (36 mm) inter-electrode distance, and in 19 (95%, p = 0.022) of those with a long distance (50.5 mm). In the bipolar group, the mean RV-to-LV interval was 72 ± 37 ms (p < 0.001 versus quadripolar). The RV-to-LV interval was > 80 ms in 44 (39%) patients (p < 0.001 versus quadripolar leads with both short and long inter-electrode distance). CONCLUSIONS: Quadripolar leads allow RV-to-LV interval maximization. An optimal RV-to-LV interval seems achievable in the majority of patients, especially if the leads present a long inter-electrode distance.

Magnitude of QRS duration reduction after biventricular pacing identifies responders to cardiac resynchronization therapy.

BACKGROUND: Several studies have investigated the association between native QRS duration (QRSd) or QRS narrowing and response to biventricular pacing. However, their results have been conflicting. The aim of our study was to determine the association between the relative change in QRS narrowing index (QI) and clinical outcome and prognosis in patients who undergo cardiac resynchronization therapy (CRT) implantation. METHODS AND RESULTS: We included 311 patients in whom a CRT device was implanted in accordance with current guidelines for CRT. On implantation, the native QRS, the QRSd and the QI during CRT were measured. After 6months, 220 (71%) patients showed a 10% reduction in LVESV. The median [25th-75th] QI was 14.3% [7.2-21.4] and was significantly related to reverse remodeling (r=+0.22; 95%CI: 0.11-0.32, p=0.0001). The cut-off value of QI that best predicted LV reverse remodeling after 6months of CRT was 12.5% (sensitivity=63.6%, specificity=57.1%, area under the curve=0.633, p=0.0002). The time to the event death or cardiovascular hospitalization was significantly longer among patients with QI>12.5% (log-rank test, p=0.0155), with a hazard ratio (HR) of 0.3 [95%CI: 0.11-0.78]. In the multivariate regression model adjusted for baseline parameters, a 10% increment in QI (HR=0.61[0.44-0.83], p=0.002) remained significantly associated with CRT response. CONCLUSIONS: Patients with a larger decrease in QRSd after CRT initiation showed greater echocardiographic reverse remodeling and better outcome from death or cardiovascular hospitalization. QI is an easy-to-measure variable that could be used to predict CRT response at the time of pacing site selection or pacing configuration programming.

Minimally invasive thoracoscopic technique for cardiac resynchronization therapy.

Outcome of surgical left ventricular (LV) lead placement is not well defined in patients with failed percutaneous cardiac resynchronization therapy. An extended experience with epicardial LV lead placement is here reported, describing the minimally invasive procedure performed at our institution using a thoracoscopic surgical approach.

Interlead anatomic and electrical distance predict outcome in CRT patients.

BACKGROUND: The implantation strategy appears to play a pivotal role in determining response to cardiac resynchronization therapy (CRT). OBJECTIVE: The aim of our study was to determine the association between anatomic and electrical interlead distance and clinical outcome after CRT implantation. METHODS: We included 216 first-time CRT recipients with left bundle branch block and sinus rhythm. On implantation, the electrical interlead distance (EID), defined as the time interval between spontaneous peak R waves detected at the right ventricular (RV) and left ventricular (LV) pacing sites, was measured. The anatomic distance between the RV and LV lead tips was determined on chest radiographs. RESULTS: The mean EID was 74 ± 41 ms, and the mean horizontal corrected interlead distance (HCID) was 125 ± 73 mm. After 12 months, 87 patients (40%) displayed an improvement in their clinical composite score. The cutoff values that best predicted an improved clinical status were as follows: 84 ms for EID (area under the curve 0.59; confidence interval [CI] 0.52-0.66; P = .026) and 90 mm for HCID (area under the curve 0.62; CI 0.55-0.69; P = .004). On multivariate analysis, only EID >84 ms (hazard ratio 0.36; CI 0.14-0.89; P = .028) and HCID >90 mm (hazard ratio 0.45; CI 0.23-0.90; P = .025) were significantly associated with the composite endpoint of death or cardiovascular hospitalization. In particular, the presence of both conditions (EID <84 ms and HCID <90 mm) was associated with the highest rate of events (log-rank test P = .002). CONCLUSIONS: The interlead anatomic and electrical distance are strongly and independently associated with patient outcome after CRT implantation. The 2 measures show an additive predictive value. (CRT MORE: Cardiac Resynchronization Therapy Modular Registry; www.clinicaltrials.gov, unique identifier: NCT01573091.)

Cardiac Resynchronization Therapy MOdular REgistry: ECG and Rx predictors of response to cardiac resynchronization therapy (NCT01573091).

AIMS: A variable proportion, up to 30%, of patients who undergo cardiac resynchronization therapy (CRT) do not benefit from treatment. The aim of the Cardiac Resynchronization Therapy MOdular REgistry (CRT MORE) is to determine whether specific electrocardiographic and radiographic parameters can be used to predict clinical and echocardiographic response to CRT. METHODS: The CRT MORE is a prospective, single-arm, multicenter cohort study designed to evaluate the electrocardiographic and radiographic predictors of response to CRT. All study patients receive a pacemaker or implantable defibrillator for CRT delivery in accordance with current guidelines. Enrollment started in December 2011 and is scheduled to end in November 2013. Approximately 1100 consecutive patients will be enrolled in 30 Italian centers and will be followed up for 60 months after implantation. The primary endpoint is the improvement in clinical (Clinical Composite Score) and echocardiographic (a decrease of ≥ 15% in left ventricular end-systolic volume) parameters at the 6-month follow-up visit. CONCLUSION: This study might provide important information about which electrocardiographic and radiographic parameters better predict CRT response.

Performance of a ventricular automatic-capture algorithm in a wide clinical setting.

BACKGROUND: The optimal programming of a pacemaker (PM) voltage output considers both efficiency (prolonging battery cell longevity) and patient safety (adequate safety margin). Currently, automatic capture (AC) algorithms are designed to ensure safe automatic stimulation threshold determination and pacing with a safety margin. METHODS: The aims of this prospective observational study were (1) to evaluate, over a short-term follow-up, the extent of backup pacing in patients implanted with an AC-featured PM produced by Boston Scientific (Insignia) and a wide range of ventricular leads; (2) to identify patient- or lead-specific predictors of ventricular threshold increase or missed detection of the ventricular pacing threshold; and (3) to analyze day-to-day fluctuations in the ventricular pacing threshold and the relationship between their magnitude, the characteristics of patients, and the system implanted. RESULTS: Five hundred and seventy-nine patients implanted with 89 different leads were followed up for a median of 2.1 months. Five hundred and thirty-six patients (92.5%) never experienced failure of automatic threshold testing; 571 (98.6%) did not experience permanent failure requiring continuous backup pacing at high energy. On multivariate analysis, none of the patient or lead characteristics predicted the occurrence of high-energy backup pacing during the study period. Day-to-day threshold fluctuations were associated only with higher thresholds (>1 V). CONCLUSION: AC algorithm reliably measures ventricular pacing thresholds in most patients: in only 1.4% of patients the system is permanently unable to detect the ventricular threshold. Backup pacing is not dependent on lead or patient characteristics, including lead polarization, polarity, and maturation.

[Percutaneous coronary revascularization in patients over eighty: acute and long-term results]. / Rivascolarizzazione coronarica percutanea nei pazienti ultraottantenni: risultati immediati e a lungo termine.

BACKGROUND: As a consequence of prolonged life expectancy the number of older patients with symptomatic coronary artery disease is constantly increasing. The aim of the study was to evaluate procedural success, immediate and long-term outcomes and the predictive factors of prognosis in patients aged > 80 years with high-risk coronary artery disease treated with coronary angioplasty. METHODS: In this retrospective study, we report the diagnostic and therapeutic strategies adopted in patients aged > 80 years admitted to our institution for acute coronary syndrome with or without ST-segment elevation or disabling angina (CCS class 3-4) and the immediate and long-term results of patients treated with coronary angioplasty. RESULTS: A conservative approach was adopted in 180 patients (33%, group 1) out of the total number of 545 patients, while 365 patients (67%, group 2) underwent coronary angiography. Among these, 85% underwent revascularization. Relevant comorbidities were significantly higher in group 1 (59 vs 16%, p < 0.001) while a clinical presentation with ST-elevation myocardial infarction was prevalent in group 2 (15 vs 6%, p = 0.007). The in-hospital mortality was 19% in group 1 and 7.9% in group 2 (p = 0.001). Among 198 patients treated with angioplasty, procedural success was achieved in 93% of cases, with 8% in-hospital mortality. Periprocedural myocardial infarction occurred in 3.3% and major bleeding in 5.6% of patients. At multivariate analysis ST-elevation myocardial infarction and cardiogenic shock were significantly related to the in-hospital mortality. At follow-up (mean 25 +/- 13 months) 13 patients died, 9 from cardiac causes and 4 from noncardiac events. Recurrence of ischemia requiring revascularization occurred in 15.9% of cases. Cumulative survival at follow-up was respectively 86% at 1 year and 83% at 5 years, while the event-free survival at 5 years was 59% in the entire group, without any significant difference among patients with multivessel disease in whom a complete vs an incomplete revascularization was performed. The presence of severe comorbidities appeared to be the only predictive factor of unfavorable outcome at long-term follow-up at multivariate analysis. CONCLUSIONS: In patients aged > 80 years with symptomatic ischemic heart disease at high risk, the invasive approach was prevalent. Higher mortality rates were found in patients in whom coronary angiography was not performed. Comorbidities represent an important negative prognostic factor, impairing both the possibility of an invasive approach and conditioning an unfavorable outcome of revascularized patients. Coronary angioplasty can be successfully performed even in elderly patients. The in-hospital mortality turns out significantly higher in the setting of an acute ST-elevation myocardial infarction or in cardiogenic shock patients. For patients overcoming the acute phase, high survival rates can be expected at follow-up.