Leadless pacemaker implantation: A feasible and reasonable option in transcatheter heart valve replacement patients.

BACKGROUND: Leadless pacemakers (LPMs) have been shown to have lower postoperative complications than traditional permanent pacemakers but there have been no studies on the outcomes of LPMs in patients with transcatheter heart valve replacements (THVRs). This study determined outcomes of LPMs compared to transvenous single-chamber pacemakers (SCPs) post-THVR. METHODS: This is a retrospective single-center study including 10 patients who received LPMs post-THVR between February 2017 and August 2018 and a comparison group of 23 patients who received SCP post-THVR between July 2008 and August 2018. LPM or SCP was implanted at the discretion of electrophysiologists for atrial fibrillation with slow ventricular response or sinus node dysfunction with need for single-chamber pacing only. RESULTS: LPMs were associated with decreased tricuspid regurgitation (P = 0.04) and decreased blood loss during implantation (7.5 ± 2.5 cc for LPMs vs 16.8 ± 3.2 cc for SCPs, P = 0.03). Five LPM patients had devices positioned in the right ventricular septum as seen on transthoracic echocardiogram. Frequency of ventricular pacing was similar between LPM and SCP groups. In the LPM group, one case was complicated by a pseudoaneurysm and one death was due to noncardiac causes. There was one pneumothorax and one pocket infection in the SCP group. CONCLUSIONS: In this small retrospective study, LPMs were feasible post-THVR and found to perform as well as SCPs, had less intraprocedural blood loss, and were associated with less tricuspid regurgitation. Further, larger studies are required to follow longer-term outcomes and complications.

Prevalence of in-hospital complications in 500 patients undergoing percutaneous coronary intervention treated with heparin 5000 IU administered systemically versus 500 age-matched and sex-matched patients treated with heparin 70 IU/kg administered systemically.

We investigated the prevalence of in-hospital complications in 500 patients undergoing percutaneous coronary intervention (PCI) treated with heparin 5000 IU administered systemically (group 1) at the time of PCI versus in 500 age-matched and sex-matched patients undergoing PCI treated with heparin 70 IU/kg administered systemically (group 2) at the time of PCI. There was no significant difference in baseline characteristics, indications for PCI, cardiovascular drug therapy at the time of PCI, prevalence of 1-vessel, 2-vessel, and 3-vessel obstructive coronary artery disease, and in-hospital complications between the 2 groups. In-hospital death occurred in 0.2% of group 1 patients versus 0.8% of group 2 patients. Non-ST-segment elevation myocardial infarction occurred in 0.2% of group 1 patients versus 0.4% of group 2 patients. Stroke occurred in 0.2% of group 1 patients versus 0.2% of group 2 patients. Stent thrombosis occurred in 0.2% of group 1 patients versus 0.8% of group 2 patients. Occlusion of a side branch occurred in 0.2% of group 1 patients versus 0.4% of group 2 patients. A hematoma needing intervention occurred in 0.2% of group 1 patients versus 0.2% of group 2 patients. Regression analysis showed that none of the differences between the 2 groups were significant. The sample size was adequate to conclude that a fixed low dose of heparin 5000 IU administered systemically at the time of PCI is noninferior to standard therapy with heparin.

Prevalence of complications during implantation and during 38-month follow-up of 1060 consecutive patients with implantable cardioverter-defibrillators.

During implantation and during 38-month follow-up of 1060 consecutive patients who had implantable cardioverter-defibrillators, complications occurred in 60 (5.7%) of 1060 patients. These complications consisted of fractured leads requiring lead revision in 36 (3.4%) patients, lead infection requiring antibiotics in 5 (0.5%) patients, device replacement because of malfunction in 5 (0.5%) patients, repositioning of leads in 3 (0.3%) patients, a hematoma at the time of implantation in 3 (0.3%) patients, pneumothorax at the time of implantation in 2 (0.2%) patients, repair of a defective generator in 1 (0.1%) patient, replacement of the device because of atrophy of the skin over the device in 1 (0.1%) patient, a transient ischemic attack because of atrial fibrillation developing during implantation in 1 (0.1%) patient, device replacement because of a recall from Guidant in 1 (0.1%) patient, pocket revision because of pain when lying on the side of the pacemaker in 1 (0.1%) patient, and pacemaker infection in 1 (0.1%) patient.

Noninvasive localization of cardiac arrhythmias using electromechanical wave imaging.

Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. The 12-lead electrocardiogram (ECG) is the current noninvasive clinical tool used to diagnose and localize cardiac arrhythmias. However, it has limited accuracy and is subject to operator bias. Here, we present electromechanical wave imaging (EWI), a high-frame rate ultrasound technique that can noninvasively map with high accuracy the electromechanical activation of atrial and ventricular arrhythmias in adult patients. This study evaluates the accuracy of EWI for localization of various arrhythmias in all four chambers of the heart before catheter ablation. Fifty-five patients with an accessory pathway (AP) with Wolff-Parkinson-White (WPW) syndrome, premature ventricular complexes (PVCs), atrial tachycardia (AT), or atrial flutter (AFL) underwent transthoracic EWI and 12-lead ECG. Three-dimensional (3D) rendered EWI isochrones and 12-lead ECG predictions by six electrophysiologists were applied to a standardized segmented cardiac model and subsequently compared to the region of successful ablation on 3D electroanatomical maps generated by invasive catheter mapping. There was significant interobserver variability among 12-lead ECG reads by expert electrophysiologists. EWI correctly predicted 96% of arrhythmia locations as compared with 71% for 12-lead ECG analyses [unadjusted for arrhythmia type: odds ratio (OR), 11.8; 95% confidence interval (CI), 2.2 to 63.2; P = 0.004; adjusted for arrhythmia type: OR, 12.1; 95% CI, 2.3 to 63.2; P = 0.003]. This double-blinded clinical study demonstrates that EWI can localize atrial and ventricular arrhythmias including WPW, PVC, AT, and AFL. EWI when used with ECG may allow for improved treatment for patients with arrhythmias.

Major adverse cardiac events at long-term follow-up in patients treated with single versus multiple stents during single-vessel percutaneous coronary intervention.

BACKGROUND: Although insertion of multiple stents into a single coronary vessel during single-vessel percutaneous coronary intervention (PCI) is common, there are no data on long-term occurrence of major adverse cardiac events (MACE) in patients treated with multiple stents versus a single stent. METHODS: The incidence of MACE (death, myocardial infarction, or target vessel revascularization) during long-term follow-up was investigated in 634 patients who underwent single-vessel PCI. Of the 634 patients, 319 (50%) had a single stent, and 315 (50%) had multiple stents inserted. Stepwise Cox regression analyses were performed to identify significant independent prognostic factors for MACE. RESULTS: At 47-month follow-up, MACE occurred in 61 of 319 patients (19%) who had a single stent versus in 57 of 315 patients (18%) who had multiple stents (P not significant). Significant independent predictors of MACE were use of vein grafts (hazard ratio = 1.94; 95% CI, 1.24-3.03; P = 0.0038) and use of drug-eluting stents (hazard ratio = 0.49; 95% CI, 0.34-0.72; P = 0.0002). CONCLUSIONS: At long-term follow-up of single-vessel PCI, the incidence of MACE was similar in patients with multiple or single stents inserted even after controlling for the length of stents.

Prevalence of appropriate cardioverter-defibrillator shocks in 1038 consecutive patients with implantable cardioverter-defibrillators.

During a 33-month follow-up of 1038 consecutive patients who had implantable cardioverter-defibrillators, appropriate shocks occurred in 329 of 1038 patients (32%). Appropriate shocks occurred in 101 of 380 patients (27%) treated with beta-adrenergic blockers alone; in 31 of 95 patients (33%) treated with amiodarone alone; in 39 of 149 patients (26%) treated with beta-blockers plus amiodarone; in 11 of 28 patients (39%) treated with sotalol alone; and in 147 of 386 patients (38%) treated with no beta-blockers, amiodarone, or sotalol (P < 0.001 comparing patients treated with beta-adrenergic blockers alone with patients treated with no beta-blockers, amiodarone, or sotalol; and P < 0.01 comparing patients treated with beta-blockers plus amiodarone with patients treated with no beta-blockers, amiodarone, or sotalol). In conclusion, patients having implantable cardioverter-defibrillators should also be treated with beta-adrenergic blockers to reduce the frequency of appropriate shocks.

Statins reduce appropriate cardioverter-defibrillator shocks and mortality in patients with heart failure and combined cardiac resynchronization and implantable cardioverter-defibrillator therapy.

Of 209 patients with heart failure treated with combined cardiac resynchronization therapy and implantable cardioverter-defibrillator therapy, appropriate cardioverter-defibrillator shocks occurred at 34-month follow-up in 22 of 121 patients (18%) on statins and in 30 of 88 patients (34%) not on statins (P = .009). Deaths occurred in 3 of 121 patients (2%) on statins and in 9 of 88 patients (10%) not on statins (P = .017). Stepwise Cox regression analysis showed that significant independent prognostic factors for appropriate shocks were use of statins (risk ratio = 0.46), smoking (risk ratio = 3.5), and diabetes (risk ratio = 0.34). Significant independent prognostic factors for the time to mortality were use of statins (risk ratio = 0.05), use of digoxin (risk ratio = 4.2), systemic hypertension (risk ratio = 14.2), diabetes (risk ratio = 4.3), and left ventricular ejection fraction (risk ratio = 1.1).

Effect of beta blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins on mortality in patients with implantable cardioverter-defibrillators.

Nine hundred sixty-five patients (mean age 70 years) with implantable cardioverter-defibrillator were followed for 32 +/- 33 months for all-cause mortality. Death occurred in 73 of 515 patients (13%) treated with beta blockers (group 1), in 84 of 494 patients (17%) treated with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (group 2), in 56 of 402 patients (14%) treated with statins (group 3), in 40 of 227 patients (18%) treated with amiodarone (group 4), in 5 of 26 patients (19%) treated with sotalol (group 5), and in 64 of 265 patients (24%) treated with no beta blocker, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, statin, amiodarone, or sotalol (group 6) (p <0.001 for group 1 vs group 6 and group 3 vs group 6, p <0.02 for group 2 vs group 6). In conclusion, patients with implantable cardioverter-defibrillators should be treated with beta blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins to reduce mortality.

Left ventricular ejection fraction and prevalence of new left ventricular wall motion abnormality at long-term follow-up in patients with automatic implantable cardioverter-defibrillators treated with dual-chamber rate-responsive pacing at a rate of 70/minute versus backup ventricular pacing at a rate of 40/minute.

Baseline and long-term follow-up 2-dimensional echocardiograms were obtained in 160 patients with automatic implantable cardioverter-defibrillators without indications for antibradycardia pacing, who had backup ventricular pacing at a rate of 40/minute (VVI-40) or dual-chamber rate-responsive pacing at a rate of 70/minute (DDDR-70). At 37 months of follow-up for 80 patients treated with VVI-40 and 23 months of follow-up for 80 patients treated with DDDR-70, the mean left ventricular ejection fraction was 36 +/- 8% at baseline and 36 +/- 8% at follow-up and 36 +/- 7% at baseline and 30 +/- 7% at follow-up (p <0.01), respectively. At follow-up, the left ventricular ejection fraction was decreased >7% in 25 of 80 patients (31%)treated with DDDR-70 and in 9 of 80 patients (11%) treated with VVI-40 (p <0.01). A new left ventricular wall motion abnormality developed in 23 of 80 patients (29%) treated with DDDR-70 and in 11 of 80 patients (14%) treated with VVI-40 (p <0.025).

Patients, mean age 70 years, with automatic implantable cardioverter-defibrillators treated with dual-chamber rate responsive pacing (DDDR-70) have a higher mortality than patients with backup ventricular pacing (VVI-40) at 3.7-year follow-up.

BACKGROUND: One study showed in 506 patients with automatic implantable cardioverter-defibrillators (AICDs) that the mortality at 1-year follow-up was 6.5% with ventricular backup pacing at 40/minute (VVI-40) versus 10.1% in patients with dual-chamber rate responsive pacing at 70/minute (DDDR-70). METHODS: We performed a retrospective study to determine all-cause mortality in all patients at a university hospital who had AICDs without indications for antibradycardia pacing. Of 535 patients, mean age 70 +/- 12 years, 271 patients had backup ventricular pacing with a VVI-40, and 264 patients had dual-chamber rate responsive pacing with a DDDR-70. RESULTS: At 3.7-year mean follow-up, all-cause mortality was 19% (50 of 264 patients) in patients with DDDR-70 pacing versus 11% (29 of 271 patients) with VVI-40 pacing (p < .01). CONCLUSION: Because of the increased mortality, increased cost, and complexity for dual-chamber rate responsive pacing in patients with AICDs, concomitant DDDR pacing at a rate of 70/minute in patients without an indication for antibradycardia pacing is not warranted.

Indications for and long-term survival in patients with automatic implantable cardioverter-defibrillators.

Automatic implantable cardioverter-defibrillators (AICDs) were implanted in 378 men and 95 women, mean age 69 +/- 12 years. At 3.6-year follow up, survival was 76% in patients who had an AICD because of cardiac arrest as a result of ventricular fibrillation or ventricular tachycardia not resulting from a transient or reversible cause; 85% in patients who had an AICD because of spontaneous sustained ventricular tachycardia in association with structural heart disease; 92% in patients who had an AICD because of syncope of undetermined origin with clinically relevant, hemodynamically sustained ventricular tachycardia or ventricular fibrillation induced at electrophysiological study when drug therapy is ineffective, not tolerated, or not preferred; 84% in patients who had an AICD because of nonsustained ventricular tachycardia with coronary artery disease, prior myocardial infarction, left ventricular dysfunction, and inducible ventricular fibrillation or sustained ventricular tachycardia at electrophysiological study that is not suppressible by a class I antiarrhythmic drug; and 85% in all 473 patients who had an AICD.

Simultaneous use of bilateral subthalamic nucleus stimulators and an implantable cardiac defibrillator. Case report.

Bilateral electrical stimulation of the subthalamic nucleus is being used with increasing frequency as a treatment for severe Parkinson disease (PD). Implantable cardiac defibrillators improve survival in certain high-risk patients with coronary artery disease and ventricular arrhythmias. Because of concern about possible interaction between these devices, deep brain stimulation (DBS) systems are routinely disconnected before defibrillators are implanted in patients with PD and arrhythmia. The authors report on a patient with bilateral subthalamic stimulators who underwent successful placement of an implantable defibrillator. Testing of the devices over a wide range of settings revealed no interaction. The patient subsequently underwent multiple episodes of cardioversion when the ventricular lead became dislodged. There was no evidence of adverse neurological effects, and interrogation of the DBS devices after cardioversion revealed no changes in stimulus parameters. The outcome in this case indicates that DBS systems may be safely retained in selected patients who require implantable cardiac defibrillators.

Incidence of appropriate cardioverter-defibrillator shocks and mortality in patients with heart failure treated with combined cardiac resynchronization plus implantable cardioverter-defibrillator therapy versus implantable cardioverter-defibrillator therapy.

Of 529 patients with heart failure and a mean left ventricular ejection fraction of 29%, 209 (40%) were treated with cardiac resynchronization therapy (CRT) plus an implantable cardioverter-defibrillator (ICD) and 320 (60%) with an ICD. Mean follow-up was 34 months for both groups. Stepwise logistic regression analysis showed that significant independent variables for appropriate ICD shocks were statins (risk ratio = 0.35, P < .0001), smoking (risk ratio = 2.52, P < .0001), and digoxin (risk ratio = 1.92, P = .0001). Significant independent variables for time to deaths were use of CRT (risk ratio = 0.32, P = .0006), statins (risk ratio = 0.18, P < .0001), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (risk ratio = 0.10, P < .0001), hypertension (risk ratio = 24.15, P < .0001), diabetes (risk ratio = 2.54, P = .0005), and age (risk ratio = 1.06, P < .0001). In conclusion, statins reduced and smoking and digoxin increased appropriate ICD shocks. Use of CRT, statins, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers reduced mortality and hypertension, diabetes, and older age increased mortality.

Risk factors for appropriate cardioverter-defibrillator shocks, inappropriate cardioverter-defibrillator shocks, and time to mortality in 549 patients with heart failure.

We investigated the risk factors for appropriate and inappropriate implantable cardioverter-defibrillator (ICD) shocks and mortality in 549 patients (mean age 74 years) with heart failure and ICDs. During a mean follow-up of 1,243 + or - 655 days, of the 549 patients, 163 (30%) had appropriate ICD shocks, 71 (13%) had inappropriate ICD shocks, and 63 (12%) died. Stepwise logistic regression analysis showed that significant independent prognostic factors for appropriate ICD shocks were smoking (odds ratio 3.7) and statins (odds ratio 0.54). The significant independent prognostic factors for inappropriate ICD shocks were atrial fibrillation (odds ratio 6.2) and statins (odds ratio 0.52). Finally, those for the interval to mortality were age (hazard ratio 1.08/1-year increase), angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (hazard ratio 0.25), atrial fibrillation (hazard ratio 4.1), right ventricular pacing (hazard ratio 3.6), digoxin (hazard ratio 2.9), hypertension (hazard ratio 5.3), and statins (hazard ratio 0.32). In conclusion, in patients with heart failure and ICDs, smoking increased and statins reduced appropriate ICD shocks, atrial fibrillation increased and statins reduced inappropriate ICD shocks, and the interval to mortality was increased by age, atrial fibrillation, right ventricular pacing, hypertension, and digoxin and reduced by angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and statins.

Major adverse cardiac events in patients with moderate to severe renal insufficiency treated with first-generation drug-eluting stents.

No data are available comparing the long-term outcome of sirolimus-eluting stents (SESs) versus paclitaxel-eluting stents (PESs) in patients with moderate to severe renal insufficiency. The incidence of major adverse cardiac events (MACE), including death, myocardial infarction, and target vessel revascularization, during long-term follow-up were studied in patients with a glomerular filtration rate of <60 ml/min/1.73 m(2), as measured by the Modification of Diet in Renal Disease (MDRD) study equation, who also underwent percutaneous coronary intervention with drug-eluting stents. Of 428 patients studied, PESs were placed in 287 patients and SESs in 141 patients. Stepwise Cox regression analyses were performed to identify significant independent risk factors for MACE. At 47 + or - 19 months of follow-up, MACE had occurred in 49 (17%) of 287 patients in the PES group (mean age 71 + or - 11 years, 55% men) and in 31 (22%) of 141 patients in the SES group (mean age 71 + or - 12 years, 53% men). No significant difference was found in the MACE rate between the PES and SES groups. This persisted even after controlling for stent length, lesion complexity, and other co-morbidities. Also, all-cause mortality was not significantly different between the PES and SES groups (7.1% vs 8.5%, respectively). In conclusion, during long-term follow-up of patients with moderate to severe renal insufficiency, the rates of MACE and all-cause mortality were similar in the PES and SES groups.

Mortality, left ventricular ejection fraction, and prevalence of new left ventricular wall motion abnormality at long-term follow-up in patients with implantable cardioverter defibrillators treated with biventricular pacing versus right ventricular pacing.

We investigated left ventricular ejection fraction and new left ventricular wall motion abnormality before pacemaker implantation and at follow-up and mortality at long-term follow-up in 81 patients with implantable cardioverter defibrillators treated with biventricular pacing and in 80 patients with implantable cardioverter defibrillators treated with DDDR-70 right ventricular pacing. At 23-month follow-up, the left ventricular ejection fraction decreased from 36% to 30% in patients treated with right ventricular pacing and increased at 38-month follow-up from 35% to 40% in patients treated with biventricular pacing (P < 0.001). New left ventricular wall motion abnormality developed at 23-month follow-up in 23 of 80 patients (29%) treated with right ventricular pacing and at 38-month follow-up in 7 of 81 patients (9%) treated with biventricular pacing (P < 0.005). Twenty-two of 80 patients (28%) treated with right ventricular pacing died at 45-month follow-up and 8 of 81 patients (10%) treated with biventricular pacing died at 53-month follow-up (P < 0.01).

Indications for implantable cardioverter defibrillator therapy.

The implantable cardioverter defibrillator (ICD) is now an integral therapy for cardiac patient care. More than 20 years have passed since the first ICD implant. Sudden cardiac death from arrhythmia (ventricular tachycardia and fibrillation) has been significantly decreased because of the use of ICD therapy. Primary treatment trials have shown ICD therapy to be superior to drug therapy. Most of these trials compared ICD therapy with amiodarone or sotalol. Prevention trials have also been completed. Patients with nonsustained ventricular tachycardia, low left ventricular ejection fraction, and coronary artery disease were evaluated with electrophysiology studies. Patients with inducible ventricular arrhythmias were treated with ICD or drug suppression therapy. ICD therapy was superior to drug therapy for prevention of fatal arrhythmias. Ongoing trials include evaluation of ICD therapy for patients with high-risk substrates: congestive heart failure, dilated cardiomyopathy, hypertrophic cardiomyopathy, and repolarization syndromes. Factors such as medication inefficacy/side effects, transvenous ICD implantation and overwhelming mortality benefits have expanded ICD usage beyond the original restrictive guidelines.