Transvenous lead extraction: Experience of the Tandem approach.

AIMS: Transvenous lead extraction (TLE) is important in the management of cardiac implantable electronic devices but carries risk. It is most commonly completed from the superior access, often with 'bail-out' support via the femoral approach. Superior and inferior access may be used in tandem, which has been proposed as an advance in safety and efficacy. The aim of this study is to evaluate the safety and efficacy of the Tandem approach. METHOD: The 'Tandem' procedure entailed grasping of the targeted lead in the right atrium to provide countertraction as a rotational dissecting sheath was advanced over the lead from the subclavian access. Consecutive 'Tandem' procedures performed by a single operator between December 2020 and March 2023 in a single large-volume TLE centre were included and compared with the conventional superior approach (control) using 1:1 propensity score matching; patients were statistically matched for demographics. RESULTS: The Tandem in comparison with the conventional approach extracted leads of much greater dwell time (148.9 ± 79 vs. 108.6 ± 77 months, P < 0.01) in a shorter procedure duration (96 ± 36 vs. 127 ± 67 min, P < 0.01) but requiring more fluoroscopy (16.4 ± 10.9 vs. 10.8 ± 14.9 min, P < 0.01). The Tandem and control groups had similar clinical (100% vs. 94.7%, P = 0.07) and complete (94.8% vs. 92.8%, P = 0.42) success, with comparable minor (4% vs. 6.7%, P = 0.72) and major (0% vs. 4%, P = 0.25) complications; procedural (0% vs. 1.3%, P = 1) and 30-day (1.3% vs. 4%, P = 0.62) mortality were also similar. CONCLUSION: The Tandem procedure is as safe and effective as the conventional TLE. It can be applied to leads of a long dwell time with a potentially shorter procedure duration.

Progress in Cardiac Resynchronisation Therapy and Optimisation.

Cardiac resynchronisation therapy (CRT) has become the cornerstone of heart failure (HF) treatment. Despite the obvious benefit from this therapy, an estimated 30% of CRT patients do not respond ("non-responders"). The cause of "non-response" is multi-factorial and includes suboptimal device settings. To optimise CRT settings, echocardiography has been considered the gold standard but has limitations: it is user dependent and consumes time and resources. CRT proprietary algorithms have been developed to perform device optimisation efficiently and with limited resources. In this review, we discuss CRT optimisation including the various adopted proprietary algorithms and conduction system pacing.

Comparison of non-laser and laser transvenous lead extraction: a systematic review and meta-analysis.

AIMS: Transvenous lead extraction (TLE) is performed using non-laser and laser techniques with overall high efficacy and safety. Variation in outcomes between the two approaches does exist with limited comparative evidence in the literature. We sought to compare non-laser and laser TLE in a meta-analysis. METHODS AND RESULTS: We searched Medline, Embase, Scopus, ClinicalTrials.gov, and CENTRAL databases for TLE studies published between 1991 and 2021. From the included 68 studies, safety and efficacy data were carefully evaluated and extracted. Aggregated cases of outcomes were used to calculate odds ratio (OR), and pooled rates were synthesized from eligible studies to compare non-laser and laser techniques. Subgroup comparison of rotational tool and laser extraction was also performed. Non-laser in comparison with laser had lower procedural mortality (pooled rate 0% vs. 0.1%, P < 0.01), major complications (pooled rate 0.7% vs. 1.7%, P < 0.01), and superior vena cava (SVC) injury (pooled rate 0% vs. 0.5%, P < 0.001), with higher complete success (pooled rate 96.5% vs. 93.8%, P < 0.01). Non-laser comparatively to laser was more likely to achieve clinical [OR 2.16 (1.77-2.63), P < 0.01] and complete [OR 1.87 (1.69-2.08), P < 0.01] success, with a lower procedural mortality risk [OR 1.6 (1.02-2.5), P < 0.05]. In the subgroup analysis, rotational tool compared with laser achieved greater complete success (pooled rate 97.4% vs. 95%, P < 0.01) with lower SVC injury (pooled rate 0% vs. 0.7%, P < 0.01). CONCLUSION: Non-laser TLE is associated with a better safety and efficacy profile when compared with laser methods. There is a greater risk of SVC injury associated with laser sheath extraction.

Transvenous Lead Extraction: Work in Progress.

Cardiac implantable electronic devices are the cornerstone of cardiac rhythm management, with a significant number of implantations annually. A rising prevalence of cardiac implantable electronic devices coupled with widening indications for device removal has fuelled a demand for transvenous lead extraction (TLE). With advancement of tools and techniques, the safety and efficacy profile of TLE has significantly improved since its inception. Despite these advances, TLE continues to carry risk of significant complications, including a superior vena cava injury and mortality. However, innovative approaches to lead extraction, including the use of the jugular and femoral accesses, offers potential for further gains in safety and efficacy. In this review, the indications and risks of TLE are discussed while examining the evolution of this procedure from simple traction to advanced methodologies, which have contributed to a significant improvement in safety and efficacy.

Contact force and catheter stability are predictive metrics of successful pulmonary vein isolation with high-power short duration ablation in atrial fibrillation.

INTRODUCTION: Preliminary data suggest that high power short duration (HPSD) ablation for pulmonary vein isolation (PVI) are safe. Limited data are available on its effectiveness. Aim was to evaluate HPSD ablation in atrial fibrillation ablation using a novel Qdot Micro catheter. METHODS AND RESULTS: Prospective multicenter study evaluating safety and efficacy of PVI with HPSD ablation. First pass isolation (FPI) and sustained PVI was assessed. If FPI was not achieved additional ablation index (AI)-guided ablation with 45 W was performed and metrics predictive of this were determined. Sixty-five patients and 260 veins were treated. Procedural and LA dwell time was 93.9 ± 30.4 and 60.5 ± 23.1 min, respectively. FPI was achieved in 47 (72.3%) patients and 231 veins (88.8%) with an ablation duration of 4.6 ± 1.0 min. Twenty-nine veins required additional AI-guided ablation to achieve initial PVI with 24 anatomical sites ablated with the right posterior carina being the most common site (37.5%). A contact force of ≥8 g (area under the curve [AUC]: 0.81; p < 0.001) and catheter position variation of ≤1.2 mm (AUC: 0.79; p < 0.001) with HPSD were strongly predictive of not requiring additional AI-guided ablation. Out of the 260 veins, only 5 (1.9%) veins showed acute reconnection. HPSD ablation was associated with shorter procedure times (93.9 vs. 159.4 min; p < 0.001), ablation times (6.1 vs. 27.7 min; p < 0.001), and lower rates of PV reconnection (9.2% vs. 30.8%; p = 0.004) compared to moderate power cohort. CONCLUSIONS: HPSD ablation is an effective ablation modality which results in effective PVI whilst maintaining a safety profile. Its superiority needs to be evaluated in randomized controlled trials.

Effect of esophageal cooling on ablation lesion formation in the left atrium: Insights from Ablation Index data in the IMPACT trial and clinical outcomes.

INTRODUCTION: The IMPACT study established the role of controlled esophageal cooling in preventing esophageal thermal injury during radiofrequency (RF) ablation for atrial fibrillation (AF). The effect of esophageal cooling on ablation lesion delivery and procedural and patient outcomes had not been previously studied. The objective was to determine the effect of esophageal cooling on the formation of RF lesions, the ability to achieve procedural endpoints, and clinical outcomes. METHODS: Participants in the IMPACT trial underwent AF ablation guided by Ablation Index (30 W at 350-400 AI posteriorly, 40 W at ≥450 AI anteriorly). A blinded 1:1 randomization assigned patients to the use of the ensoETM® device to keep esophageal temperature at 4°C during ablation or standard practice using a single-sensor temperature probe. Ablation parameters and clinical outcomes were analyzed. RESULTS: Procedural data from 188 patients were analyzed. Procedure and fluoroscopy times were similar, and all pulmonary veins were isolated. First-pass pulmonary vein isolation and reconnection at the end of the waiting period were similar in both randomized groups (51/64 vs. 51/68; p = 0.54 and 5/64 vs. 7/68; p = 0.76, respectively). Posterior wall isolation was also similar: 24/33 versus 27/38; p = 0.88. Ablation effect on tissue, measured in impedance drop, was no different between the two randomized groups: 8.6Ω (IQR: 6-11.8) versus 8.76Ω (IQR: 6-12.2; p = 0.25). Arrhythmia recurrence was similar after 12 months (21.1% vs. 24.1%; 95% CI: 0.38-1.84; HR: 0.83; p = 0.66). CONCLUSIONS: Esophageal cooling has been shown to be effective in reducing ablation-related thermal injury during RF ablation. This protection does not compromise standard procedural endpoints or clinical success at 12 months.

Catheter Ablation for Atrial Fibrillation in Patients with Chronic Kidney Disease and on Dialysis: A Meta-Analysis and Review.

BACKGROUND: Atrial fibrillation (AF) is common in chronic kidney disease (CKD) patients and is difficult to treat with anti-arrhythmics and anticoagulants due to abnormal metabolism and increased side effects. Catheter ablation, if successful, may be a safer alternative. This review aimed to analyse the effect of CKD or haemodialysis (HD) on recurrence of AF after catheter ablation. METHODS: MEDLINE, Embase, and PubMed databases were searched until December 2020. Two authors abstracted the data independently. Relative risks were derived using random-effects meta-analysis. RESULTS: Of the initially identified 782 studies, 6 and 4 observational studies investigating CKD and HD patients, respectively reported AF recurrence rates. During a mean (SD) follow-up of 25.5 (9.8) months, CKD patients demonstrated a higher risk of AF recurrence compared to patients without CKD (RR 2.34, 95% CI: 1.36-4.02, p < 0.01). The heterogenicity test highlighted significant differences between individual studies (I2 = 91.0%, 95% CI: 82.2-95.6%). In a mean (SD) follow-up of 32.6 (26.8) months, HD patients may be at a higher risk of AF recurrence compared to healthy non-dialysis AF patients (RR 1.50, 95% CI: 0.84-2.67, p = 0.17). Heterogeneity analysis showed the studies were heterogeneous (I2 = 90.1%, 95% CI: 77.5-95.6%, p < 0.01). CONCLUSION: Our meta-analysis suggests patients with CKD and on HD are more likely to have AF recurrences compared to AF patients who do not have CKD. However, more robust evidence from randomized controlled trials comparing catheter ablation to pharmaceutical rhythm therapy is urgently needed to guide therapy in this difficult to treat population.

Triple access transvenous lead extraction: Pull-through of a lead from subclavian to jugular access to facilitate extraction.

A 39-years old ventricular lead of a right-sided single-chamber pacemaker required extraction for infection. Angulation at the right subclavian-superior vena cava junction coupled with calcified fibrotic encapsulating tissue prevented advancement of a rotational dissecting sheath. To straighten the lead, it was pulled from the subclavian and out of the right internal jugular vein, whilst the Needle's-Eye Snare via the femoral access provided counter-traction. A 13-french rotational dissecting sheath was successfully advanced over the lead via the jugular access to complete the lead extraction without any complication.

New approaches to achieving hemostasis after venous access in cardiovascular patients.

Recent decades have seen a series of advances in percutaneous transvenous procedures for cardiac arrhythmias, including the implantation of leadless pacemakers. Many of these procedures require the insertion of large caliber sheaths in large veins, usually the femoral vein. Securing hemostasis efficiently and reliably at the access site is a key step to improving a procedure's safety profile. Traditionally, hemostasis was achieved by manual compression of venous access sites, but the trend toward larger sheaths and the increased use of uninterrupted anticoagulation has pushed the limits of this method. Achieving hemostasis by compression alone in these circumstances requires more attention and longer duration, leading to greater patient discomfort and prolonged immobility. In turn, manual compression may be more time-consuming for medical professionals and increase the number of occupied hospital beds. New approaches have been developed to facilitate early ambulation, decrease patient discomfort, and address the risk of access site complications. These approaches include vascular closure devices and subcutaneous suture techniques including figureof- eight and purse-string sutures. This article reviews the new approaches applied to achieve venous access site hemostasis in patients undergoing transvenous procedures for cardiac arrhythmias.

Anatomical variations in coronary venous drainage: Challenges and solutions in delivering cardiac resynchronization therapy.

AIMS: To investigate the abnormalities of the coronary venous system in candidates for cardiac resynchronization therapy (CRT) and describe methods for circumventing the resulting difficulties. METHODS: From four implanting institutes, data of all CRT implants between October 2008 and October 2020 were screened for abnormal cardiac venous anatomy, defined as an anatomical variation not conforming to the accepted 'normal' anatomy. Patient demographics, procedural detail, and subsequent left ventricle (LV) lead pacing indices were collected. RESULTS: From a total of 3548 CRT implants, 15 (0.42%) patients (80% male) of 72.2 ± 10.6 years in age with an LV ejection fraction of 34 ± 10.3% were identified to have had an abnormal cardiac venous anatomy over the study period. There were 13 cases of persistent left side superior vena cava (pLSVC), five of which had coronary sinus ostium atresia (CSOA) including two with an "unroofed" coronary sinus (CS); one patient had a unique anomalous origin of the CS and one patient had an isolated CSOA. In total 14 patients (60% repeat attempt) had successful percutaneous implant under general anesthesia (46.7%) via the cephalic vein (59.1%), using the femoral approach (53.3%) for levophase venography and/or pull-through, including one case of endocardial LV implant. Pacing follow-up over 37.64 ± 37.6 months demonstrated LV lead threshold between 0.62 and 2.9 volts (pulsewidth 0.4-1.5 ms) in all cases; five patients died within 2.92 ± 1.6 years of a successful implant. CONCLUSION: CRT devices can be implanted percutaneously even in the presence of substantial abnormalities of coronary venous anatomy. Alternative routes of venous access may be required.

Patient related outcomes of mechanical lead extraction techniques (PROMET) study: A comparison of two professions.

BACKGROUND: With an increasing number of cardiac implantable electronic devices (CIEDs), there has been a paralleled increase in demand for transvenous lead extraction (TLE). Cardiac surgeons (CS) and cardiologists perform TLE; however, data comparing the two groups of operators is scarce. OBJECTIVE: We compared the outcomes of TLE performed by cardiologists and CS from six European lead extraction units. METHOD: Data was collected retrospectively of 2205 patients who had 3849 leads extracted (PROMET) between 2005 and 2018. Patient demographics and procedural outcomes were compared between the CS and cardiologist groups, using propensity score matching. A multivariate regression analysis was also performed for variables associated with 30-day mortality. RESULTS: CS performed the majority of extractions (59.8%), of leads with longer dwell times (90 [57-129 interquartile range (IQR)] vs. 62 [31-102 IQR] months, CS vs. cardiologists, p < .001) and with pre-dominantly non-infectious indications (57.4% vs. 50.2%, CS vs. cardiologists, p < .001). CS achieved a higher complete success per lead than the cardiologists (98.1% vs. 95.7%, respectively, p < .01), with a higher number of minor complications (5.51% vs. 2.1%, p < .01) and similar number of major complications (0.47% vs. 1.3%, p = .12). Thirty-day mortality was similarly low in the CS and cardiologist groups (1.76% vs. 0.94%, p = .21). Unmatched data multivariate analysis revealed infection indication (OR 6.12 [1.9-20.3], p < .01), procedure duration (OR 1.01 [1.01-1.02], p < .01) and CS operator (OR 2.67, [1.12-6.37], p = .027) were associated with 30-day mortality. CONCLUSION: TLE by CS was performed with similar safety and higher efficacy compared to cardiologists in high and medium-volume lead extraction centers.

Rationale and study design of the MINERVA study: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction-UK multicentre collaboration.

INTRODUCTION: The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication. METHODS AND ANALYSIS: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non-invasive programmed electrical stimulation protocol via the implanted device. All participants will undergo the EP study hence no randomisation is required. Participants will be followed up over a minimum of 18 months and up to 3 years. The first patient was recruited in August 2016 and the study will be completed at the final participant follow-up visit. The primary endpoint is ventricular fibrillation or sustained ventricular tachycardia >200 beats/min as recorded by the ICD. The secondary endpoint is SCD. Analysis of the ECG data obtained during the EP study will be performed by the core lab where blinding of patient health status and endpoints will be maintained. ETHICS AND DISSEMINATION: Ethical approval has been granted by Research Ethics Committees Northern Ireland (reference no. 16/NI/0069). The results will inform the design of a definitive Randomised Controlled Trial (RCT). Dissemination will include peer reviewed journal articles reporting the qualitative and quantitative results, as well as presentations at conferences and lay summaries. TRIAL REGISTRATION NUMBER: NCT03022487.

ILEEM-survey on the Heart Team approach and team training for lead extraction procedures.

BACKGROUND: The Heart Team approach has become an integral part of modern cardiovascular medicine. To evaluate current opinions and real-world practice among lead extraction practitioners, an online survey was created and distributed among a pool of lead extraction specialists participating in the International Lead Extraction Expert Meeting (ILEEM) 2018. METHODS: The online survey consisted of 10 questions and was performed using an online survey tool (www.surveymonkey.com). The collector link was sent to 48 lead extraction experts via email. RESULTS: A total of 43 answers were collected (89% return rate) from lead extraction experts in 16 different countries. A great majority (83.7%) of the respondents performed more than 30 lead extraction procedures per year. The most common procedural environment in this survey was the hybrid operating room (67.4%). Most procedures were performed by electrophysiologists and cardiologists (80.9%). Important additional members of the current lead extraction teams were cardiac surgeons (79.1%), anesthesiologists (95.3%) and operating room scrub nurses (76.7%). An extended Heart Team is regarded beneficial for patient care by 86.0%, with potential further members being infectious diseases specialists, intensivists and radiologists. Team training activities are performed in 48.8% of participating centers. CONCLUSIONS: This survey supports the importance of establishing lead extraction Heart Teams in specialized lead extraction centers to potentially improve patient outcomes. The concept of a core and an extended Heart Team approach in lead extraction procedures is introduced.

Hourly variability in outflow tract ectopy as a predictor of its site of origin.

INTRODUCTION: Before ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. METHODS: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-h ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left-sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. RESULTS: High VE variability (coefficient of variation ≥0.7) and the presence of any hour with <50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). CONCLUSION: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favorably to existing ECG algorithms.

Persistent left superior vena cava transvenous lead extraction: A European experience.

BACKGROUND: Transvenous lead extraction (TLE) is rising in parallel to cardiac implantable electronic device implantations. Persistent left side superior vena cava (PLSVC) is a relatively common anatomical variant in the healthy population; TLE in patients with a PLSVC is rare. METHOD: Data were collated from 6 European TLE institutes of 10 patients who had undergone lead extraction with a PLSVC. Patient demographics, procedural challenges and outcomes were reported. RESULTS: Ten patients aged 73.4 ± 7.8 years (60% male) underwent TLE of 20 leads (3 left ventricle, 10 right ventricle, 7 right atrium) with dwell time of 82.95 ± 39.1 months. Of the 10 cases, 4 had an infection indication and 5 were biventricular system extractions; 25% of the extracted leads were defibrillator leads. The majority of the procedures were completed in the cardiac catheterization suite (80%) under general anaesthesia (60%) by cardiologists (80%) using a rotational powered sheath (65%). The Tandem approach was used successfully in 3 cases. Complete procedural success was obtained in 100% of cases in the absence of complications within 127.4 ± 74.7 min. There was no 30-day mortality. CONCLUSION: TLE in PLSVC is feasible albeit rare. Standard extraction techniques in experienced hands are associated with favorable outcomes; the Tandem procedure may be an additional technique to improve the safety and efficacy of TLE in PLSVC.

Transvenous lead extraction: The influence of age on patient outcomes in the PROMET study cohort.

BACKGROUND: Cardiac implantable electronic device (CIED) therapy contributes to an improvement in morbidity and mortality across all patient demographics. Patient age is a recognized risk factor for unfavorable outcomes in invasive procedures. This is the largest series of non-laser transvenous lead extraction (TLE) evaluating the association between patient age and procedure outcomes. METHODS: Data of 2205 (3849 leads) patients was collected retrospectively from six European TLE centers between January 2005-December 2018 in the PROMET study. Of these, 153 patients with 319 leads were excluded for incomplete data. A comparison of outcomes was performed between the age groups young [< 50 years], young intermediate [50-69 years], older intermediate [70-79 years], and octogenarian [≥80 years]. RESULTS: Infection was most common indication for TLE in the octogenarian cohort, less common in the younger population (60.1% vs. 33.2%, respectively, p < .01). High-voltage leads were extracted most frequently from young patients, less frequently from octogenarians (31.6% vs. 10%, p < .001), while the opposite was evident for pacemaker leads (p < .001). Rotational sheath use was equally prevalent across all patient groups (p = .79). Minor and major complications across all the age groups were statistically similar, as was procedural success; the 30-day mortality was most significant in the octogenarian and least in the young patients (4.9% vs. 0.4%, p = .005). Propensity matching multivariate analysis found systemic infection, lead dwell time, and patient age (p = .013, OR 1.064 [1.013-1.116]) increased risk of 30-day mortality. CONCLUSION: TLE is safe and effective across all age groups. 30-day mortality risk is significantly higher in the older patients.

Prevalence of bradyarrhythmias needing pacing in COVID-19.

BACKGROUND: The Sars-Cov-2 infection is a multisystem illness that can affect the cardiovascular system. Tachyarrhythmias have been reported but the prevalence of bradyarrhythmia is unclear. Cases have been described of transient high-degree atrioventricular (AV) block in COVID-19 that were managed conservatively. METHOD: A database of all patients requiring temporary or permanent pacing in two linked cardiac centers was used to compare the number of procedures required during the first year of the pandemic compared to the corresponding period a year earlier. The database was cross-referenced with a database of all patients testing positive for Sars-Cov-2 infection in both institutions to identify patients who required temporary or permanent pacing during COVID-19. RESULTS: The number of novel pacemaker implants was lower during the COVID-19 pandemic than the same period the previous year (540 vs. 629, respectively), with a similar proportion of high-degree AV block (38.3% vs. 33.2%, respectively, p = .069). Four patients with the Sars-Cov-2 infection had a pacemaker implanted for high-degree AV block, two for sinus node dysfunction. Of this cohort of six patients, two succumbed to the COVID-19 illness and one from non-COVID sepsis. Device interrogation demonstrated a sustained pacing requirement in all cases. CONCLUSION: High-degree AV block remained unaltered in prevalence during the COVID-19 pandemic. There was no evidence of transient high-degree AV block in patients with the Sars-Cov-2 infection. Our experience suggests that all clinically significant bradyarrhythmia should be treated by pacing according to usual protocols regardless of the COVID status.

A multicenter prospective randomized controlled trial of cardiac resynchronization therapy guided by invasive dP/dt.

BACKGROUND: No periprocedural metric has demonstrated improved cardiac resynchronization therapy (CRT) outcomes in a multicenter setting. OBJECTIVE: We sought to determine if left ventricular (LV) lead placement targeted to the coronary sinus (CS) branch generating the best acute hemodynamic response (AHR) results in improved outcomes at 6 months. METHODS: In this multicenter randomized controlled trial, patients were randomized to guided CRT or conventional CRT. Patients in the guided arm had LV dP/dtmax measured during biventricular (BIV) pacing. Target CS branches were identified and the final LV lead position was the branch with the best AHR and acceptable threshold values. The primary endpoint was the proportion of patients with a reduction in LV end-systolic volume (LVESV) of ≥15% at 6 months. RESULTS: A total of 281 patients were recruited across 12 centers. Mean age was 70.8 ± 10.9 years and 54% had ischemic etiology. Seventy-three percent of patients in the guided arm demonstrated a reduction in LVESV of ≥15% at 6 months vs 60% in the conventional arm (P = .02). Patients with AHR ≥ 10% were more likely to demonstrate a reduction of ESV ≥ 15% (84% of patients with an AHR ≥10% vs 28% with an AHR <10%; P < 0.001). Procedure duration and fluoroscopy times were longer in the pressure wire-guided arm (104 ± 39 minutes vs 142 ± 39 minutes; P < .001 and 20 ±16 minutes vs 28 ± 15 minutes; P = .002). CONCLUSIONS: AHR determined by invasively measuring LV dP/dtmax during BIV pacing predicts reverse remodeling 6 months after CRT. Patients in whom LV dP/dtmax was used to guide LV lead placement demonstrated better rates of reverse remodeling.