Domenico G. Della Rocca

Left ventricular pacing with a new quadripolar transvenous lead for CRT: Early results of a prospective comparison with conventional implant outcomes

BACKGROUND Flexible left ventricular (LV) pacing configurations are a useful component of cardiac resynchronization therapy (CRT) systems for preventing high LV pacing thresholds and phrenic nerve stimulation (PNS). A quadripolar LV lead has recently been designed with the purpose of allowing more choices in lead placement location and programming capability. OBJECTIVE To verify the effectiveness of quadripolar LV leads compared to conventional bipolar LV leads implant outcomes. METHODS Forty-five consecutive patients underwent implantation with either the quadripolar (n = 22; quadripolar group) or a conventional bipolar LV lead (n = 23; bipolar group). The primary outcome of the study was LV lead failure, defined as the need for lead revision or reprogramming during the first 3 months after implantation. Additionally, operative and follow-up data were prospectively noted and checked for significance between groups. RESULTS The implantation success rate in both groups was 100%. Baseline characteristics, procedure duration, and fluoroscopy time did not differ significantly between groups. Two lead dislodgments (requiring reoperation) and 4 clinical PNS were reported in the bipolar group; reprogramming of the device was sufficient to prevent PNS in 3 patients, the fourth is pending solution. One PNS successfully managed noninvasively occurred in the quadripolar group. By Kaplan-Meier analysis, event-free survival for the combined primary outcome was significantly lower in patients with quadripolar leads (P = .037). CONCLUSION This prospective, controlled study provides strong evidence that CRT with the quadripolar LV lead results in low rates of dislocations and phrenic nerve stimulation.

Clinical and procedural outcome of patients implanted with a quadripolar left ventricular lead: Early results of a prospective multicenter study

BACKGROUND Recent studies suggest that cardiac resynchronization therapy (CRT) with a quadripolar left ventricular (LV) lead results in low rates of dislocation and phrenic nerve stimulation (PNS) acutely and at short-term follow-up. Confirmation of these results by long-term observational studies is needed. OBJECTIVE To evaluate the long-term procedural and clinical outcomes of CRT patients implanted with a quadripolar LV lead. METHODS A total of 154 consecutive heart failure patients (79% men, age 68 ± 10 years) having CRT implantation attempts with a quadripolar LV lead were included in this observational registry. Demographic and clinical data were preoperatively collected, and patients were followed up for at least 6 months. RESULTS The overall implant success rate after coronary sinus cannulation was 97.4%. Mean overall duration and fluoroscopy time of successful procedures was 112 ± 22 and 16 ± 8 minutes, respectively, while 17 ± 13 minutes were necessary for the LV lead placement. After implant, the conventional bipolar configuration was used as the final pacing configuration in 33.3% of the patients. Four lead dislodgments (requiring reoperation) and 9 clinical PNS were reported during follow-up; reprogramming of the device was sufficient to prevent PNS in all patients. Once placed, the LV lead remained stable with excellent pacing thresholds during follow-up (15 ± 5 months). Overall, there were 71.3% CRT responders as assessed by 6-month echocardiography, and 66% improved at least 1 New York Heart Association class. CONCLUSION Over the longer term, CRT with the quadripolar LV lead is associated with excellent pacing thresholds, low rates of dislocations, and PNS.

Safety and efficacy of a new magnetic resonance imaging-compatible pacing system: early results of a prospective comparison with conventional dual-chamber implant outcomes.

BACKGROUND A new pacing system has been designed and tested preclinically for safe use in the magnetic resonance imaging (MRI) environment. Experience with this innovative system has not yet been reported. OBJECTIVE The purpose of this study was to verify the safety and effectiveness of this newly designed system compared to conventional DDD implant outcomes. METHODS Over an 11-month period, 107 consecutive patients (71 men and 36 women; age 72.6 +/- 8.5 years) were implanted with either the MRI system (n = 50; MRI group) or a dual-chamber, active-fixation lead (Medtronic 4076) non-MRI system (n = 57; DDD group). Data were collected at implant and during postoperative follow-up at 1, 3, 6, and 12 months. Procedural and fluoroscopic times at implant, as well as lead measurements, handling characteristics, and procedural-related complications, were prospectively analyzed. RESULTS The implantation success rate in both groups was 100%. Cephalic access was 63% for MRI patients and 70% for DDD patients (P = NS). Follow-up was obtained for all patients (median 6.8 months, range 3-12 months). At implant and at the end of follow-up, stimulation thresholds, sensing, and impedance were acceptable. No cases of high pacing thresholds or inadequate sensing were noted. No complications occurred, and no patient experienced subsequent lead displacement. CONCLUSION This prospective, controlled study provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional technique.

Impact of continuous intracardiac ST-segment monitoring on mid-term outcomes of ICD-implanted patients with coronary artery disease. Early results of a prospective comparison with conventional ICD outcomes

Background Although myocardial ischaemia monitored by some implantable cardioverter-defibrillators (ICDs) might improve patient care, the clinical usefulness of this technology has not yet been validated. Objective To investigate the potential impact of ICD-based ischaemia monitoring on clinical care and patient management of ICD recipients. Design Prospective, controlled, non-randomised study. Setting Single-centre, university hospital. Patients Consecutive patients with known coronary artery disease, followed up for at least 6 months. Interventions Patients implanted with either an ICD providing continuous intracardiac ST monitoring (n=53; ST group) or with an ICD without this capability (n=50). Main outcome measures Major cardiovascular events, appropriateness of ST-shift episodes and unscheduled device-related visits. Results During follow-up (15.4±8.4 months), one patient experienced ST-shift events confirmed by angiography to be related to myocardial ischaemia. Myocardial infarction was a rare event and occurred in one patient (ST group) who had an ST-elevation myocardial infarction 3 weeks after the implant, but at this time the algorithm had not yet been activated. In the ST group, seven patients had one or more episodes of false-positive ST events (median 9, range 1–90). The programmable features of the device helped overcome the problem in six patients. Among patients with a remote monitoring system, unscheduled outpatient visits were significantly increased in the ST group (17 vs 4; p=0.032). Conclusions Although, this study was underpowered by the small number of acute ischaemic events, ICD-based ST monitoring failed to provide a benefit over ICDs without this capability and increased unscheduled evaluations in patients with remote follow-up. The sensitivity and specificity of the algorithm still require validation.

Predictive value of fragmented QRS in primary prevention implantable cardioverter defibrillator recipients with left ventricular dysfunction.

Introduction In primary prevention implantable cardioverter defibrillator (ICD) patients, the incidence of appropriate ICD therapy is relatively low, prompting better risk stratification. Fragmented QRS (fQRS) on a 12-lead ECG has been associated with adverse outcomes. The aim of this study was to evaluate the prognostic value of fQRS in ICD recipients. Methods Consecutive ICD patients implanted at our institution for primary prevention of sudden cardiac death (SCD) were retrospectively evaluated. Patients were divided in two groups based on the presence or the absence of fQRS on the ECG obtained before ICD implantation. The endpoint of the study was all-cause mortality or the occurrence of any appropriate ICD-delivered therapy, whether shock or antitachycardia pacing. Results Among 394 ICD recipients (334 men, age 66.4 ± 11.0), fQRS was observed in 103 patients (26.1%). There were 189 patients (48.0%) with wide QRS at the time of implantation. Among these patients, fQRS was found in 29 individuals (28.2%). Patients in fQRS(+) group were more likely to have coronary artery disease and a lower QRS duration than those without fQRS. During a mean follow-up of 26.3 ± 17.5 months, mortality or ICD therapy were 19.4 and 22.4%, respectively, for fQRS(+) patients, and 15.2 and 22.8% for fQRS(−) patients (P = NS). By Kaplan–Meier analysis, event-free survival was similar in the two groups. Conclusion In ICD recipients for primary prevention of SCD, fQRS is not helpful in selecting a subgroup of patients who benefit from prophylactic ICD implantation.

Endothelium as a predictor of adverse outcomes.

The authors have no funding, financial relationships, or conflicts of interest to disclose.

Long-Term Outcome of Pulmonary Vein Isolation With and Without Focal Impulse and Rotor Modulation Mapping: Insights From a Meta-Analysis

Background: This meta-analysis systematically evaluated the outcome of pulmonary vein isolation (PVI) with and without focal impulse and rotor modulation (FIRM) ablation in patients with atrial fibrillation. Methods and Results: Extensive literature search was performed for studies reporting outcomes of PVI alone and PVI+FIRM procedures. For PVI alone, only randomized trials conducted in the past 3 years reporting single-procedure off-antiarrhythmic drugs success rate at ≥12-month follow-up were included. In PVI+FIRM group, all published studies reporting single-procedure off-antiarrhythmic drugs success rate with at least 1-year follow-up were identified. Meta-analytic estimates were derived using DerSimonian and Laird random-effects models, and pooled estimates of success rate (95% confidence interval) were computed. Statistical heterogeneity was assessed using Cochran Q test and I2. Study quality was assessed using Newcastle–Ottawa Scale. Fifteen trials were included, 10 with PVI+FIRM (n=511, nonrandomized prospective design), and 5 with PVI-only trials (n=295, randomized trials). All patients in PVI-only trials had 100% nonparoxysmal atrial fibrillation, except 1 study, and no prior ablations. About 24% of PVI+FIRM population had paroxysmal atrial fibrillation. After 15.9±5.5 (median 12) months follow-up, the off-antiarrhythmic drugs pooled success rate was 50% in FIRM+PVI (95% confidence interval, 28%–72%) and 58% in PVI (95% confidence interval, 46%–71%). Difference in effect size between groups was not statistically significant (P=0.21). No significant heterogeneity (total or within group) was observed in this meta-analysis (negative I2 values considered equal to zero). Conclusions: The overall pooled estimate did not show any therapeutic benefit of PVI+FIRM approach over PVI alone, which suggests the need to reevaluate the clinical use of FIRM ablation in atrial fibrillation.

Acute left hemothorax as a late complication of an active-fixation pacemaker lead.

Perforation and migration of pacemaker electrodes into the pleural cavity is a rare event. We report the clinical course and surgical treatment of massive acute hemothorax resulting from intercostal artery laceration, caused by a retained active-fixation pacing lead implanted 10 months earlier.

Without a quadripolar left ventricular lead you don't succeed: A challenging case of phrenic nerve stimulation

A 61-year-oldwhitemalewas admitted to our hospital pursuant to complaints of shortness of breath and precordial pain especially during physically laborious work. He had been well until 1 month previously. The patient was a former smoker with dyslipidemia and hypertension. His medical history revealed a diagnosis of idiopathic dilated cardiomyopathy 3 years earlier. The patient was hemodynamically stable at admission, with a blood pressure of 130/90 mm Hg. Electrocardiogram showed sinus tachycardia, left bundle branch block (QRS duration 160 ms), poor R wave progression and T wave inversion in the lateral leads. The echocardiographic study demonstrated a severely dilated left ventricle (LV end-diastolic diameter 62 mm) and an overall depressed systolic function (estimated ejection fraction 30%) with marked dyssynchrony of the ventricular function. The patient underwent cardiac catheterization due to his clinical presentation and was negative for significant focal coronary artery obstruction. Despite optimal medical therapy, he was symptomatic of heart failure; hence, we decided to implant a CRT-D device (Promote Q, St. JudeMedical Inc., Sylmar, CA). The left ventricular pacing lead was the Quartet lead: a 4.7 F over-the-wire, steroid eluting lead with a 4-electrode in-line connector that enables delivery of pacing stimuli using any of the 4 electrodes as the cathode in 10 pacing configurations. The procedure was successfully completed and the D1-M2 configuration was chosen because of satisfactory electrical parameters and absence of PNS

What Causes Myocardial Infarction in Women Without Obstructive Coronary Artery Disease

Women experience higher mortality rates and more adverse outcomes after acute myocardial infarction (AMI) than men, despite less obstructive coronary artery disease (CAD) and plaque burden with similar plaque responses to intensive risk factor modification.1 Furthermore, nonobstructive CAD by angiography appears to be emerging as a predictor of mortality in women, but not among men.2 These puzzling findings illustrate our incomplete understanding of sex-specific differences in pathophysiological mechanisms of AMI and ischemic heart disease in general. A better understanding of the mechanisms would lead the way for improvement in attempts to optimize ischemic heart disease management among women. Article see p1414 In the current issue, Reynolds and colleagues3 provide new data to help advance our understanding in this area by using intravascular ultrasound (IVUS) and cardiac magnetic resonance imaging (CMR) to investigate women with AMI in the absence of obstructive CAD. They provide the first evidence for plaque disruption and myocardial tissue characteristics among women with confirmed AMI and normal or only minimally abnormal coronary angiograms. To help interpret their novel findings, it seems appropriate to briefly review what we know in this area. Although sex-related results were lacking, autopsy studies from past decades securely linked severe atherosclerotic CAD and intracoronary thrombosis with AMI leading to death. More recent and detailed studies of women and men dying with AMI added disrupted plaque as the culprit for the acute thrombotic event. Overall, the majority had plaque rupture; a third had erosion; and a few percent had calcified nodules contributing to the thrombi.4 Interestingly, plaque erosion was identified as the cause of death in about one third of women, whereas in men, erosion was only about half as frequent as the cause of death. More important, erosion was observed as the cause of acute coronary thrombi in …