LV cathode position in CRT recipients: How can we benefit from CMR?

BACKGROUND: Left ventricular lead positioning represents a key step in CRT optimization. However, evidence for its guidance based on specific topographical factors and related imaging techniques is sparse. OBJECTIVE: To analyze reverse remodeling (RR) and clinical events in CRT recipients based on LV cathode (LVC) position relative to latest mechanical activation (LMA) and scar as determined by cardiac magnetic resonance (CMR). METHODS: This is a retrospective single-center study of 68 consecutive Q-LV-guided CRT-D and CRT-P recipients. Through CMR-based 3D reconstructions overlayed on fluoroscopy images, LVCs were stratified as concordant, adjacent, or discordant to LMA (3 segments with latest and greatest radial strain) and scar (segments with >50% scar transmurality). The primary endpoint of RR (expressed as percentage ESV change) and secondary composite endpoint of HF hospitalizations, LVAD/heart transplant, or cardiovascular death were compared across categories. RESULTS: LVC proximity to LMA was associated with a progressive increase in RR (percentage ESV change: concordant -47.0 ± 5.9%, adjacent -31.4 ± 3.1%, discordant +0.4 ± 3.7%), while proximity to scar was associated with sharply decreasing RR (concordant +10.7 ± 12.9%, adjacent +0.3 ± 5.3%, discordant -31.3 ± 4.4%, no scar -35.4 ± 4.8%). 4 integrated classes of LVC position demonstrated a significant positive RR gradient the more optimal the category (class I -47.0 ± 5.9%, class II -34.9 ± 2.8%, class III -5.5 ± 4.3%, class IV + 3.4 ± 5.2%). Freedom from composite secondary endpoint of HF hospitalization, LVAD/heart transplant, or cardiovascular death confirmed these trends demonstrating significant differences across both integrated as well as individual LMA and scar categories. CONCLUSION: Integrated CMR-determined LVC position relative to LMA and scar stratifies response to CRT.

Benefits of upgrading right ventricular to biventricular pacing in heart failure patients with atrial fibrillation.

AIMS: Recommendations on cardiac resynchronization therapy (CRT) in patients with atrial fibrillation or flutter (AF) are based on less robust evidence than those in sinus rhythm (SR). We aimed to assess the efficacy of CRT upgrade in the BUDAPEST-CRT Upgrade trial population by their baseline rhythm. METHODS AND RESULTS: Heart failure patients with reduced ejection fraction (HFrEF) and previously implanted pacemaker (PM) or implantable cardioverter defibrillator (ICD) and ≥20% right ventricular (RV) pacing burden were randomized to CRT with defibrillator (CRT-D) upgrade (n = 215) or ICD (n = 145). Primary [HF hospitalization (HFH), all-cause mortality, or <15% reduction of left ventricular end-systolic volume] and secondary outcomes were investigated. At enrolment, 131 (36%) patients had AF, who had an increased risk for HFH as compared with those with SR [adjusted hazard ratio (aHR) 2.99; 95% confidence interval (CI) 1.26-7.13; P = 0.013]. The effect of CRT-D upgrade was similar in patients with AF as in those with SR [AF adjusted odds ratio (aOR) 0.06; 95% CI 0.02-0.17; P < 0.001; SR aOR 0.13; 95% CI 0.07-0.27; P < 0.001; interaction P = 0.29] during the mean follow-up time of 12.4 months. Also, it decreased the risk of HFH or all-cause mortality (aHR 0.33; 95% CI 0.16-0.70; P = 0.003; interaction P = 0.17) and improved the echocardiographic response (left ventricular end-diastolic volume difference -49.21 mL; 95% CI -69.10 to -29.32; P < 0.001; interaction P = 0.21). CONCLUSION: In HFrEF patients with AF and PM/ICD with high RV pacing burden, CRT-D upgrade decreased the risk of HFH and improved reverse remodelling when compared with ICD, similar to that seen in patients in SR.

Benefits of upgrading right ventricular to biventricular pacing in heart failure patients with atrial fibrillation.

AIMS: Recommendations on cardiac resynchronization therapy (CRT) in patients with atrial fibrillation or flutter (AF) are based on less robust evidence than those in sinus rhythm (SR). We aimed to assess the efficacy of CRT upgrade in the BUDAPEST-CRT Upgrade trial population by their baseline rhythm. METHODS AND RESULTS: Heart failure patients with reduced ejection fraction (HFrEF) and previously implanted pacemaker (PM) or implantable cardioverter defibrillator (ICD) and ≥20% right ventricular (RV) pacing burden were randomized to CRT with defibrillator (CRT-D) upgrade (n = 215) or ICD (n = 145). Primary [HF hospitalization (HFH), all-cause mortality, or <15% reduction of left ventricular end-systolic volume] and secondary outcomes were investigated. At enrolment, 131 (36%) patients had AF, who had an increased risk for HFH as compared with those with SR [adjusted hazard ratio (aHR) 2.99; 95% confidence interval (CI) 1.26-7.13; P = 0.013]. The effect of CRT-D upgrade was similar in patients with AF as in those with SR [AF adjusted odds ratio (aOR) 0.06; 95% CI 0.02-0.17; P < 0.001; SR aOR 0.13; 95% CI 0.07-0.27; P < 0.001; interaction P = 0.29] during the mean follow-up time of 12.4 months. Also, it decreased the risk of HFH or all-cause mortality (aHR 0.33; 95% CI 0.16-0.70; P = 0.003; interaction P = 0.17) and improved the echocardiographic response (left ventricular end-diastolic volume difference -49.21 mL; 95% CI -69.10 to -29.32; P < 0.001; interaction P = 0.21). CONCLUSION: In HFrEF patients with AF and PM/ICD with high RV pacing burden, CRT-D upgrade decreased the risk of HFH and improved reverse remodelling when compared with ICD, similar to that seen in patients in SR.

Selection of candidates for cardiac resynchronization therapy and implantation management: an Italian survey promoted by the Italian Association of Arrhythmology and Cardiac Pacing.

BACKGROUND: Cardiac resynchronization therapy (CRT) represents an effective heart failure treatment, associated with reduction in mortality and heart failure hospitalizations. This Italian survey aimed to address relevant CRT issues. METHODS: An online survey was administered to AIAC members. RESULTS: One hundred and five electrophysiologists participated, with a median of 40 (23-70) CRT implantations/year (33% in high-volume centres). Forty-five percent of respondents (especially working in high-volume centres) reported an increase in CRT implantations in the last 2 years, in 16% a decrease, and in 38% CRT remained stable. Seventy-five percent of respondents implanted CRT only in patients with European Heart Rhythm Association (EHRA) class I indications. All operators collected ECG and echocardiography before implantation. Eighty-five percent of respondents selected coronary sinus target vein empirically, whereas 10% used mechanical and/or electrical delay techniques. Physicians working in high-volume centres reported a lower failure rate compared with others (16 vs. 34%; P = 0.03). If the coronary sinus lead could not be positioned in the target branch, 80% placed it in another vein, whereas 16% opted for a surgical approach or for conduction system pacing (CSP). Eighty percent accomplished CRT optimization in all patients, 17% only in nonresponders. Regarding anticoagulation, high agreement with EHRA guidelines emerged. CONCLUSION: CRT represents a valid therapeutic option in heart failure treatment. Nowadays, CRT implantations remain stable and are mainly performed in patients with class I indications. ECG remains the preferred tool for patient selection, whereas imaging is increasingly used to determine the left pacing target area. In most patients, the left ventricular lead can be successfully positioned in the target vein, but in some cases, the result can be unsatisfactory; however, the decision to explore alternative resynchronization approaches is rarely pursued.

Impact of Immunosuppressive Therapy on Lead Dislodgement After Cardiac Implantable Electronic Device Implantation.

BACKGROUNDS: Lead dislodgement is a severe complication in cardiac implantable electronic device (CIED) implantation. Inflammation after CIED implantation results in the development of adhesions between lead and tissues, resulting in the lead becoming fixed in the body. In patients with immunosuppressive therapy, however, adhesion is inhibited by anti-inflammatory effects. However, the association between lead dislodgement and immunosuppressive therapy has not been clarified. The purpose of this study was to investigate the association between lead dislodgement and immunosuppressive therapy. HYPOTHESIS: We hypothesized that lead dislodgement more frequently occur in patients with immunosuppressive therapy than those without. METHODS: In total, 651 consecutive patients who underwent CIED implantation or lead addition (age, 76 ± 11 years; and males, 374 [58%], high voltage device, 121 [19%], lead addition 23 [4%]) were retrospectively enrolled. Immunosuppressive therapy was with regular steroids or immunosuppressants. Lead placement was guided by fluoroscopy, and active fixation leads were used. Restraint of the upper limb by chest tape was performed for 1 week after the procedure. Lead dislodgement was defined as a change in lead position and/or lead failure requiring reoperation. RESULTS: Twenty (3.1%) patients received immunosuppressive therapy. Among these, 15 (2.3%) patients regularly took steroids and 8 (1.2%) took immunosuppressants. Lead dislodgement occurred in 10 (1.5%) patients. Lead dislodgement was more frequent in patients with immunosuppressive therapy than in those without (3 [15%] vs. 7 [1%], p = 0.003). CONCLUSION: In patients with CIED implantation or lead addition, lead dislodgement is more frequent in patients with immunosuppressive therapy than in those without.

A novel method combining gated SPECT and vectorcardiography to guide left ventricular lead placement to improve response to cardiac resynchronization therapy: A proof of concept study.

BACKGROUND: The segment of the latest mechanical contraction (LMC) does not always overlap with the site of the latest electrical activation (LEA). By integrating both mechanical and electrical dyssynchrony, this proof-of-concept study aimed to propose a new method for recommending left ventricular (LV) lead placements, with the goal of enhancing response to cardiac resynchronization therapy (CRT). METHODS: The LMC segment was determined by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) phase analysis. The LEA site was detected by vectorcardiogram. The recommended segments for LV lead placement were as follows: (1) the LMC viable segments that overlapped with the LEA site; (2) the LMC viable segments adjacent to the LEA site; (3) If no segment met either of the above, the LV lateral wall was recommended. The response was defined as ≥15% reduction in left ventricular end-systolic volume (LVESV) 6-months after CRT. Patients with LV lead located in the recommended site were assigned to the recommended group, and those located in the non-recommended site were assigned to the non-recommended group. RESULTS: The cohort comprised of 76 patients, including 54 (71.1%) in the recommended group and 22 (28.9%) in the non-recommended group. Among the recommended group, 74.1% of the patients responded to CRT, while 36.4% in the non-recommended group were responders (P = .002). Compared to pacing at the non-recommended segments, pacing at the recommended segments showed an independent association with an increased response by univariate and multivariable analysis (odds ratio 5.00, 95% confidence interval 1.73-14.44, P = .003; odds ratio 7.33, 95% confidence interval 1.53-35.14, P = .013). Kaplan-Meier curves showed that pacing at the recommended LV lead position demonstrated a better long-term prognosis. CONCLUSION: Our findings indicate that pacing at the recommended segments, by integrating of mechanical and electrical dyssynchrony, is significantly associated with an improved CRT response and better long-term prognosis.

Accidental Conduction System Pacing in Patient with Displaced Cardiac Resynchronization Therapy Leads.

A 69-year-old woman with a history of heart failure with reduced ejection fraction presented for device interrogation of her cardiac implantable electronic device (CIED), revealing lead and pulse generator displacement. Surprisingly, she exhibited a narrow QRS on the ECG despite an underlying right bundle branch block, suggesting unintentional conduction system pacing (CSP). Traditional cardiac resynchronization therapy has been widely used for patients with heart failure, but alternatives like CSP are emerging as viable options. Given the global rise in CIED utilization, regular follow-up, device troubleshooting, and embracing remote monitoring are essential to manage and optimize patient outcomes.

Trends and disparities in cardiac implantable electronic device infection-related mortality in the United States.

INTRODUCTION: We performed a cross-sectional study using the Centers for Disease Control and Prevention's (CDC's) Wide-Ranging Online Data for Epidemiologic Research (WONDER) database to analyze the trends in cardiac implantable electronic device (CIED) infection-related mortality from 1999 to 2020. METHODS: We analyzed the death certificate data from the CDC WONDER database from 1999 to 2020 for CIED infections in the US population aged ≥25 years using International Classification of Diseases, Tenth Revision (ICD-10) codes, listed as the underlying or contributing cause of death. Age-adjusted mortality rates (AAMR) and 95% confidence intervals (CIs) were computed per 1 million population by standardizing crude mortality rates to the 2000 US census population. To assess annual mortality trends, we employed the Joinpoint regression model, calculating the annual percent change (APC) in AAMR and corresponding 95% CIs. RESULTS: Overall, there was an observed declining trend in AAMRs related to CIED infection-related mortality. Males accounted for 55% of the total deaths, with persistently higher AAMRs compared to females over the study duration. Both males and females had an overall decreasing trend in AAMRs throughout the study duration. On race/ethnicity stratified analysis, non-Hispanic (NH) Blacks exhibited the highest overall AAMR, followed by NH American Indians or Alaska Natives, NH Whites, Hispanic or Latinos, and NH Asian or Pacific Islanders. On a stratified analysis based on region, the South region had the highest overall AAMR, followed by the Midwest, West, and Northeast regions. CONCLUSION: Our study demonstrates a significant decline in CIED infection-related mortality in patients over the last two decades. Notable gender, racial/ethnic, and regional differences exist in the rates of mortality related to CIED infections.

Cardiac Devices and Kidney Disease.

A growing variety of cardiac devices are available to monitor or support cardiovascular function. The entwined nature of cardiovascular disease and kidney disease makes the relationship of these devices with kidney disease a multifaceted question relating to the use of these devices in individuals with kidney disease and to the effects of the devices and device placement on kidney health. Cardiac devices can be categorized broadly into cardiac implantable electronic devices, structural devices, and circulatory assist devices. Cardiac implantable electronic devices include devices for monitoring and managing cardiac electrical activity and devices for monitoring hemodynamics. Structural devices modify cardiac structure and include valve prostheses, valve repair clips, devices for treating atrial septal abnormalities, left atrial appendage closure devices, and interatrial shunt devices. Circulatory assist devices support the failing heart or support cardiac function during high-risk cardiac procedures. Evidence for the use of these devices in individuals with kidney disease, effects of the devices on kidney health and function, specific considerations with devices in kidney disease, and important knowledge gaps are surveyed in this article. With the growing prevalence of combined cardiorenal disease and the increasing variety of cardiac devices, kidney disease considerations are an important aspect of device therapy.

Economic Considerations of Cardiovascular Implantable Electronic Devices for The Treatment of Heart Failure.

PURPOSE OF REVIEW: Heart failure (HF) is a major public health problem worldwide, affecting more than 64 million people [1]. The complex and severe nature of HF presents challenges in providing cost-effective care as patients often require multiple hospitalizations and treatments. This review of relevant studies with focus on the last 10 years summarizes the health and economic implications of various HF treatment options in Europe and beyond. Although the main cost drivers in HF treatment are clinical (re)admission and decompensation of HF, an assessment of the economic impacts of various other device therapy options for HF care are included in this review. This includes: cardiovascular implantable electronic devices (CIEDs) such as cardiac-resynchronisation-therapy devices that include pacemaking (CRT-P), cardiac-resynchronisation-therapy devices that include defibrillation (CRT-D), implantable cardioverter/defibrillators (ICDs) and various types of pacemakers. The impact of (semi)automated (tele)monitoring as a relevant factor for increasing both the quality and economic impact of care is also taken into consideration. Quality of life adjusted life years (QALYs) are used in the overall context as a composite metric reflecting quantity and quality of life as a standardized measurement of incremental cost-effectiveness ratios (ICER) of different device-based HF interventions. RECENT FINDINGS: In terms of the total cost of different devices, CRT-Ds were found in several studies to be more expensive than all other devices in regards to runtime and maintenance costs including (re)implantation. In the case of CRT combined with an implantable cardioverter-defibrillator (CRT-D) versus ICD alone, CRT-D was found to be the most cost-effective treatment in research work over the past 10 years. Further comparison between CRT-D vs. CRT-P does not show an economic advantage of CRT-D as a minority of patients require shock therapy. Furthermore, a positive health economic effect and higher survival rate is seen in CRT-P full ventricular stimulation vs. right heart only stimulation. Telemedical care has been found to provide a positive health economic impact for selected patient groups-even reducing patient mortality. For heart failure both in ICD and CRT-D subgroups the given telemonitoring benefit seems to be greater in higher-risk populations with a worse HF prognosis. In patients with HF, all CIED therapies are in the range of commonly accepted cost-effectiveness. QALY and ICER calculations provide a more nuanced understanding of the economic impact these therapies create in the healthcare landscape. For severe cases of HF, CRT-D with telemedical care seems to be the better option from a health economic standpoint, as therapy is more expensive, but costs per QALY range below the commonly accepted threshold.

Interaction of left ventricular size with the outcome of cardiac resynchronization therapy in Japanese patients.

BACKGROUND: We analyzed the influence of the QRS duration (QRSd) to LV end-diastolic volume (LVEDV) ratio on cardiac resynchronization therapy (CRT) outcomes in heart failure patients classified as III/IV per the New York Heart Association (NYHA) and with small body size. HYPOTHESIS: We proposed the hypothesis that the QRSd/LV size ratio is a better index of the CRT substrate. METHODS: We enrolled 114 patients with advanced heart failure (NYHA class III/IV, and LV ejection fraction >35%) who received a CRT device, including those with left bundle branch block (LBBB) and QRSd ≥120 milliseconds (n = 60), non-LBBB and QRSd ≥150 milliseconds (n = 30) and non-LBBB and QRSd of 120-149 milliseconds (n = 24). RESULTS: Over a mean follow-up period of 65 ± 58 months, the incidence of the primary endpoint, a composite of all-cause death and hospitalization for heart failure, showed no significant intergroup difference (43.3% vs. 50.0% vs. 37.5%, respectively, p = .72). Similarly, among 104 patients with QRSd/LVEDV ≥ 0.67 (n = 54) and QRSd/LVEDV < 0.67 (n = 52), no significant differences were observed in the incidence of the primary endpoint (35.1% vs. 51.9%, p = .49). Nevertheless, patients with QRSd/LVEDV ≥ 0.67 showed better survival than those with QRSd/LVEDV < 0.67 (14.8% vs. 34.6%, p = .0024). CONCLUSION: Advanced HF patients with a higher QRSd/LVEDV ratio showed better survival in this small-body-size population. Thus, the risk is concentrated among those with a larger QRSd, and patients with a relatively smaller left ventricular size appeared to benefit from CRT.

Outcomes of tricuspid regurgitation after lead extraction.

INTRODUCTION: Transvenous leads have been implicated in tricuspid valve (TV) dysfunction, but limited data are available regarding the effect of extracting leads across the TV on valve regurgitation. The aim of this study is to quantify tricuspid regurgitation (TR) before and after lead extraction and identify predictors of worsening TR. METHODS: We studied 321 patients who had echocardiographic data before and after lead extraction. TR was graded on a scale (0 = none/trivial, 1 = mild, 2 = moderate, 3 = severe). A change of >1 grade following extraction was considered significant. RESULTS: A total of 321 patients underwent extraction of a total of 338 leads across the TV (1.05 ± 0.31 leads across the TV per patient). There was no significant difference on average TR grade pre- and postextraction (1.18 ± 0.91 vs. 1.15 ± 0.87; p = 0.79). TR severity increased after extraction in 84 patients, but was classified as significantly worse (i.e., >1 grade change in severity) in only 8 patients (2.5%). Use of laser lead extraction was associated with a higher rate of worsening TR postextraction (44.0% vs. 31.6%, p = 0.04). CONCLUSION: In our single-center analysis, extraction of leads across the TV did not significantly affect the extent of TR in most patients. Laser lead extraction was associated with a higher rate of worsening TR after extraction.

Determination of sensed and paced atrial-ventricular delay in cardiac resynchronization therapy.

BACKGROUND: Optimization of atrial-ventricular delay (AVD) during atrial sensing (SAVD) and pacing (PAVD) provides the most effective cardiac resynchronization therapy (CRT). We demonstrate a novel electrocardiographic methodology for quantifying electrical synchrony and optimizing SAVD/PAVD. METHODS: We studied 40 CRT patients with LV activation delay. Atrial-sensed to RV-sensed (As-RVs) and atrial-paced to RV-sensed (Ap-RVs) intervals were measured from intracardiac electrograms (IEGM). LV-only pacing was performed over a range of SAVD/PAVD settings. Electrical dyssynchrony (cardiac resynchronization index; CRI) was measured at each setting using a multilead ECG system placed over the anterior and posterior torso. Biventricular pacing, which included multiple interventricular delays, was also conducted in a subset of 10 patients. RESULTS: When paced LV-only, peak CRI was similar (93 ± 5% vs. 92 ± 5%) during atrial sensing or pacing but optimal PAVD was 61 ± 31 ms greater than optimal SAVD. The difference between As-RVs and Ap-RVs intervals on IEGMs (62 ± 31 ms) was nearly identical. The slope of the correlation line (0.98) and the correlation coefficient r (0.99) comparing the 2 methods of assessing SAVD-PAVD offset were nearly 1 and the y-intercept (0.63 ms) was near 0. During simultaneous biventricular (BiV) pacing at short AVD, SAVD and PAVD programming did not affect CRI, but CRI was significantly (p < .05) lower during atrial sensing at long AVD. CONCLUSIONS: A novel methodology for measuring electrical dyssynchrony was used to determine electrically optimal SAVD/PAVD during LV-only pacing. When BiV pacing, shorter AVDs produce better electrical synchrony.

Cardiac implantable electronic devices and bloodstream infections: management and outcomes.

BACKGROUND AND AIMS: Bloodstream infection (BSI) of any cause may lead to device infection in cardiac implantable electronic device (CIED) patients. Aiming for a better understanding of the diagnostic approach, treatment, and outcome, patients with an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy and defibrillator (CRT-D) hospitalized with BSI were investigated. METHODS: This is a single-centre, retrospective, cohort analysis including consecutive ICD/CRT-D patients implanted between 2012 and 2021. These patients were screened against a list of all hospitalized patients having positive blood cultures consistent with diagnosed infection in any department of a local public hospital. RESULTS: The total cohort consisted of 515 patients. Over a median follow-up of 59 months (interquartile range 31-87 months), there were 47 BSI episodes in 36 patients. The majority of patients with BSI (92%) was admitted to non-cardiology units, and in 25 episodes (53%), no cardiac imaging was performed. Nearly all patients (85%) were treated with short-term antibiotics, whereas chronic antibiotic suppression therapy (n = 4) and system extraction (n = 3) were less frequent. Patients with BSI had a nearly seven-fold higher rate (hazard ratio 6.7, 95% confidence interval 3.9-11.2; P < .001) of all-cause mortality. CONCLUSIONS: Diagnostic workup of defibrillator patients with BSI admitted to a non-cardiology unit is often insufficient to characterize lead-related endocarditis. The high mortality rate in these patients with BSI may relate to underdiagnosis and consequently late/absence of system removal. Efforts to increase an interdisciplinary approach and greater use of cardiac imaging are necessary for timely diagnosis and adequate treatment.