Conduction System Pacing vs Biventricular Pacing in Heart Failure and Wide QRS Patients: LEVEL-AT Trial.

BACKGROUND: Conduction system pacing (CSP) has emerged as an alternative to biventricular pacing (BiVP). Randomized studies comparing both therapies are scarce and do not include left bundle branch pacing. OBJECTIVES: This study aims to compare ventricular resynchronization achieved by CSP vs BiVP in patients with cardiac resynchronization therapy indication. METHODS: LEVEL-AT (Left Ventricular Activation Time Shortening with Conduction System Pacing vs Biventricular Resynchronization Therapy) was a randomized, parallel, controlled, noninferiority trial. Seventy patients with cardiac resynchronization therapy indication were randomized 1:1 to BiVP or CSP, and followed up for 6 months. Crossover was allowed when primary allocation procedure failed. Primary endpoint was the change in left ventricular activation time, measured using electrocardiographic imaging. Secondary endpoints were left ventricular reverse remodeling and the combined endpoint of heart failure hospitalization or death at 6-month follow-up. RESULTS: Thirty-five patients were allocated to each group. Eight (23%) patients crossed over from CSP to BiVP; 2 patients (6%) crossed over from BiVP to CSP. Electrocardiographic imaging could not be performed in 2 patients in each group. A similar decrease in left ventricular activation time was achieved by CSP and BiVP (-28 ± 26 ms vs -21 ± 20 ms, respectively; mean difference -6.8 ms; 95% CI: -18.3 ms to 4.6 ms; P < 0.001 for noninferiority). Both groups showed a similar change in left ventricular end-systolic volume (-37 ± 59 mL CSP vs -30 ± 41 mL BiVP; mean difference: -8 mL; 95% CI: -33 mL to 17 mL; P = 0.04 for noninferiority) and similar rates of mortality or heart failure hospitalizations (2.9% vs 11.4%, respectively) (P = 0.002 for noninferiority). CONCLUSIONS: Similar degrees of cardiac resynchronization, ventricular reverse remodeling, and clinical outcomes were attained by CSP as compared to BiVP. CSP could be a feasible alternative to BiVP. (LEVEL-AT [Left Ventricular Activation Time Shortening With Conduction System Pacing vs Biventricular Resynchronization Therapy]; NCT04054895).

Forty-Year Trends in Cardiac Implantable Electronic Device Infective Endocarditis.

Background: Studies investigating cardiac implantable electronic device infective endocarditis (CIED-IE) epidemiological changes and prognosis over long periods of time are lacking. Methods: Retrospective single cardiovascular surgery center cohort study of definite CIED-IE episodes between 1981-2020. A comparative analysis of two periods (1981-2000 vs 2001-2020) was conducted to analyze changes in epidemiology and outcome over time. Results: One-hundred and thirty-eight CIED-IE episodes were diagnosed: 25 (18%) first period and 113 (82%) second. CIED-IE was 4.5 times more frequent in the second period, especially in implantable cardiac defibrillators. Age (63 [53-70] vs 71 [63-76] years, P < .01), comorbidities (CCI 3.0 [2-4] vs 4.5 [3-6], P > .01), nosocomial infections (4% vs 15.9%, P = .02) and transfers from other centers (8% vs 41.6%, P < .01) were significantly more frequent in the second period, as were methicillin-resistant coagulase-negative staphylococcal (MR-CoNS) (0% vs 13.3%, P < .01) and Enterococcus spp. (0% vs 5.3%, P = .01) infections, pulmonary embolism (0% vs 10.6%, P < .01) and heart failure (12% vs 28.3%, p < .01). Second period surgery rates were lower (96% vs 87.6%, P = .09), and there were no differences in in-hospital (20% vs 11.5%, P = .11) and one-year mortalities (24% vs 15%, P = .33), or relapses (8% vs 5.3%, P = 0.65). Multivariate analysis showed Charlson index (hazard ratios [95% confidence intervals]; 1.5 [1.16-1.94]) and septic shock (23.09 [4.57-116.67]) were associated with a worse prognosis, whereas device removal (0.11 [.02-.57]), transfers (0.13 [.02-0.95]), and second-period diagnosis (0.13 [.02-.71]) were associated with better one-year outcomes. Conclusions: CIED-IE episodes increased more than four-fold during last 40 years. Despite CIED-IE involved an older population with more comorbidities, antibiotic-resistant MR-CoNS, and complex devices, one-year survival improved.

Ventricular arrhythmia risk is associated with myocardial scar but not with response to cardiac resynchronization therapy.

AIMS: Sudden cardiac death (SCD) risk estimation in patients referred for cardiac resynchronization therapy (CRT) remains a challenge. By CRT-mediated improvement of left ventricular ejection fraction (LVEF), many patients loose indication for primary prevention implantable cardioverter-defibrillator (ICD). Increasing evidence shows the importance of myocardial scar for risk prediction. The aim of this study was to investigate the prognostic impact of myocardial scar depending on the echocardiographic response in patients undergoing CRT. METHODS AND RESULTS: Patients with indication for CRT were prospectively enrolled. Decision about ICD or pacemaker implantation was based on clinical criteria. All patients underwent delayed-enhancement cardiac magnetic resonance imaging. Median follow-up duration was 45 (24-75) months. Primary outcome was a composite of sustained ventricular arrhythmia, appropriate ICD therapy, or SCD. A total of 218 patients with LVEF 25.5 ± 6.6% were analysed [158 (73%) male, 64.9 ± 10.7 years]. Myocardial scar was observed in 73 patients with ischaemic cardiomyopathy (ICM) (95% of ICM patients); in 62 with non-ischaemic cardiomyopathy (45% of these patients); and in all but 1 of 36 (17%) patients who reached the primary outcome. Myocardial scar was the only significant predictor of primary outcome [odds ratio 27.7 (3.8-202.7)], independent of echocardiographic CRT response. A total of 55 (25%) patients died from any cause or received heart transplant. For overall survival, only a combination of the absence of myocardial scar with CRT response was associated with favourable outcome. CONCLUSION: Malignant arrhythmic events and SCD depend on the presence of myocardial scar but not on CRT response. All-cause mortality improved only with the combined absence of myocardial scar and CRT response.

HACEK infective endocarditis: Epidemiology, clinical features, and outcome: A case-control study.

OBJECTIVES: The study aimed to describe the epidemiological, microbiological, and clinical features of a population sample of 17 patients with HACEK infective endocarditis (HACEK-IE) and to compare them with matched control patients with IE caused by viridans group streptococci (VGS-IE). METHODS: Cases of definite (n=14, 82.2%) and possible (n=3, 17.6%) HACEK-IE included in the Infective Endocarditis Hospital Clinic of Barcelona (IE-HCB) database between 1979 and 2016 were identified and described. Furthermore, a retrospective case-control analysis was performed, matching each case to three control subjects with VGS-IE registered in the same database during the same time period. RESULTS: Seventeen out of 1209 IE cases (1.3%, 95% confidence interval 0.69-1.91%) were due to HACEK group organisms. The most frequently isolated HACEK species were Aggregatibacter spp (n=11, 64.7%). Intracardiac vegetations were present in 70.6% of cases. Left heart failure (LHF) was present in 29.4% of cases. Ten patients (58.8%) required in-hospital surgery and none died during hospitalization. In the case-control analysis, there was a trend towards larger vegetations in the HACEK-IE group (median (interquartile range) size 11.5 (10.0-20.0) mm vs. 9.0 (7.0-13.0) mm; p=0.068). Clinical manifestations, echocardiographic findings, LHF rate, systemic emboli, and other complications were all comparable (p>0.05). In-hospital surgery and mortality were similar in the two groups. One-year mortality was lower for HACEK-IE (1/17 vs. to 6/48; p=0.006). CONCLUSIONS: HACEK-IE represented 1.3% of all IE cases. Clinical features and outcomes were comparable to those of the VGS-IE control group. Despite the trend towards a larger vegetation size, the embolic event rate was not higher and the 1-year mortality was significantly lower for HACEK-IE.

Postprocedural LGE-CMR comparison of laser and radiofrequency ablation lesions after pulmonary vein isolation.

INTRODUCTION: The purpose of this study was to compare the anatomical characteristics of scar formation achieved by visual-guided laser balloon (Laser) and radiofrequency (RF) pulmonary vein isolation (PVI), using late-gadolinium-enhanced cardiac magnetic resonance imaging (LGE-CMR). METHODS AND RESULTS: We included 17 patients with paroxysmal or early persistent drug resistant AF who underwent Laser ablation; 2 were excluded due to procedure-related complications. The sample was matched with a historical group of 15 patients who underwent PVI using RF. LGE-CMR sequences were acquired before and 3 months post-PVI. Ablation gaps were defined as pulmonary vein (PV) perimeter sections showing no gadolinium enhancement. The number of ablation gaps was lower in Laser versus RF ablations (median 7 vs. 14, P  =  0.015). Complete anatomical PVI (circumferential scar around PV, without gaps) was more frequently achieved with Laser than with RF (39% vs. 19% of PVs, P  =  0.025). Fewer gaps were present at the superior and anterior left PV and posterior right PV antral regions in the Laser group, compared to RF. Scar extension into the PVs was similar in both groups, although RF produced more extensive ablation scar toward the LA body. AF recurrences at 1 year were similar in both groups (Laser 36% vs. RF 27%, P  =  1.00). CONCLUSIONS: Compared to RF, Laser ablation achieved more complete anatomical PVI, with less LA scar extension. However, AF recurrence appears to be similar after Laser compared to RF ablation. Further studies are needed to assess whether the anatomical advantages of Laser ablation translate into clinical benefit in patients with AF.

Clinical presentation of CIED infection following initial implant versus reoperation for generator change or lead addition.

Objective: To explore differences in clinical manifestations and outcomes in those patients who develop infection after undergoing initial implantation versus reoperation. Methods: We compared cases of cardiac implantable electronic device (CIED) infection based on initial implantation versus reoperation from 11 centres. Results: There were 432 patients with CIED infection, 178 occurring after initial device placement and 254 after repeat reoperation. No differences were seen in age, sex or device type. Those with infection after initial implant had a higher Charlson Comorbidity Score (median 3 (IQR 2-6) vs 2 (IQR 1-4), p<0.001), shorter time since last procedure (median 8.9 months (IQR 0.9-33.3) vs 19.5 months (IQR 1.1-62.9), p<0.0001) and fewer leads (2.0±0.6vs 2.5±0.9, p<0.001). Pocket infections were more likely to occur after a reoperation (70.1%vs48.9%, p<0.001) and coagulase negative staphylococci (CoNS) was the most frequently isolated organism in this group (p=0.029). In contrast, initial implant infections were more likely to present with higher white cell count (10.5±5.1 g/dL vs 9.5±5.4 g/dL, p=0.025), metastatic foci of infection (16.9%vs8.7%, p=0.016) and sepsis (30.9%vs19.3%, p=0.006). There were no differences in in-hospital (7.9%vs5.2%, p=0.31) or 6-month mortality (21.9%vs14.0%, p=0.056). Conclusions: CIED infections after initial device implant occur earlier, more aggressively, and often due to Staphylococcus aureus. In contrast, CIED infections after reoperation occur later, are due to CoNS, and have more indolent manifestations with primary localisation to the pocket.

Epidemiology, Clinical Features, and Outcome of Infective Endocarditis due to Abiotrophia Species and Granulicatella Species: Report of 76 Cases, 2000-2015.

Background: Infective endocarditis (IE) caused by Abiotrophia (ABI) and Granulicatella (GRA) species is poorly studied. This work aims to describe and compare the main features of ABI and GRA IE. Methods: We performed a retrospective study of 12 IE institutional cases of GRA or ABI and of 64 cases published in the literature (overall, 38 ABI and 38 GRA IE cases). Results: ABI/GRA IE represented 1.51% of IE cases in our institution between 2000 and 2015, compared to 0.88% of HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella)-related IE and 16.62% of Viridans group streptococci (VGS) IE. Institutional ABI/GRA IE case characteristics were comparable to that of VGS, but periannular complications were more frequent (P = .008). Congenital heart disease was reported in 4 (10.5%) ABI and in 11 (28.9%) GRA cases (P = .04). Mitral valve was more frequently involved in ABI than in GRA (P < .001). Patient sex, prosthetic IE, aortic involvement, penicillin susceptibility, and surgical treatment were comparable between the genera. New-onset heart failure was the most frequent complication without genera differences (P = .21). Five (13.2%) ABI patients and 2 (5.3%) GRA patients died (P = .23). Factors associated with higher mortality were age (P = .02) and new-onset heart failure (P = .02). The genus (GRA vs ABI) was not associated with higher mortality (P = .23). Conclusions: GRA/ABI IE was more prevalent than HACEK IE and approximately one-tenth as prevalent as VGS; periannular complications were more frequent. GRA and ABI genera IE presented similar clinical features and outcomes. Overall mortality was low, and related to age and development of heart failure.

Elucidation of hidden slow conduction by double ventricular extrastimuli: a method for further arrhythmic substrate identification in ventricular tachycardia ablation procedures.

Aims: Identification of local abnormal electrograms (EGMs) during ventricular tachycardia substrate ablation (VTSA) is challenging when they are hidden within the far-field signal. This study analyses whether the response to a double ventricular extrastimulus during substrate mapping could identify slow conducting areas that are hidden during sinus rhythm. Methods and results: Consecutive patients (n = 37) undergoing VTSA were prospectively included. Bipolar EGMs with >3 deflections and duration <133 ms were considered as potential hidden slow conduction EGMs (HSC-EGM) if located within/surrounding the scar area. Whenever a potential HSC-EGM was identified, a double ventricular extrastimulus was delivered. If the local potential delayed, it was annotated as HSC-EGM. The incidence of HSC-EGM in core, border-zone, and normal-voltage regions was determined. Ablation was delivered at conducting channel entrances and HSC-EGMs. VT inducibility after VTSA obtained was compared with data from a historic control group. 2417 EGMs were analyzed. 575 (23.7%) qualified as potential HSC-EGM, and 198 of them were tagged as HSC-EGMs. Scars in patients with HSC-EGMs (n = 21, 56.7%) were smaller (35.424.7 vs 67.639.1 cm2; P = 0.006) and more heterogeneous (core/scar area ratio 0.250.2 vs 0.450.19; P = 0.02). 28.8% of HSC-EGMs were located in normal-voltage tissue; 81.3% were targeted for ablation. Patients undergoing VTSA incorporating HSC analysis needed less radiofrequency time (17.411 vs 2310.7 minutes; P = 0.016) and had a lower rate of VT inducibility after VTSA than the historic controls (24.3% vs 50%; P = 0.018). Conclusion: Ventricular tachycardia substrate ablation incorporating HSC analysis allowed further arrhythmic substrate identification (especially in normal-voltage areas) and reduced RF time and VT inducibility after VTSA.

Diagnostic Accuracy of 18F-FDG PET/CT in Infective Endocarditis and Implantable Cardiac Electronic Device Infection: A Cross-Sectional Study.

Early diagnosis of infective endocarditis (IE) is based on the yielding of blood cultures and echocardiographic findings. However, they have limitations and sometimes the diagnosis is inconclusive, particularly in patients with prosthetic valves (PVs) and implantable cardiac electronic devices (ICEDs). The primary aim of this study was to evaluate the diagnostic accuracy of 18F-FDG PET/CT in patients with suspected IE and ICED infection. METHODS: A prospective study with 80 consecutive patients with suspected IE and ICED infection (65 men and 15 women with a mean age of 68 ± 13 y) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria were clinically suspected IE and ICED infection at the following locations: native valve (NV) (n = 21), PV (n = 29), or ICED (n = 30) (automatic implantable defibrillator [n = 11] or pacemaker [n = 19]). Whole-body 18F-FDG PET/CT with a myocardial uptake suppression protocol with unfractionated heparin was performed in all patients. The final diagnosis of infection was established by the IE Study Group according to the clinical, echocardiographic, and microbiologic findings. RESULTS: A final diagnosis of infection was confirmed in 31 patients: NV (n = 6), PV (n = 12), and ICED (n = 13). Sensitivity, specificity, positive predictive value, and negative predictive value for 18F-FDG PET/CT were 82%, 96%, 94%, and 87%, respectively. 18F-FDG PET/CT was false-negative in all cases with infected NV. 18F-FDG PET/CT was able to reclassify 63 of 70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18 of 70 cases, 18F-FDG PET/CT changed possible to definite IE (26%) and in 45 of 70 cases changed possible to rejected IE (64%). Additionally, 18F-FDG PET/CT identified 8 cases of septic embolism and 3 of colorectal cancer in patients with a final diagnosis of IE. CONCLUSION: 18F-FDG PET/CT proved to be a useful diagnostic tool in suspected IE and ICED infection and should be included in the diagnostic algorithm for early diagnosis. 18F-FDG PET/CT is not useful in the diagnosis of IE in NV but should be also considered in the initial assessment of this complex scenario to rule out extracardiac complications and possible neoplasms.