Aveir VR real-world performance and chronic pacing threshold prediction using mapping and fixation electrical data.

AIMS: Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated. METHODS: Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width. RESULTS: Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000). CONCLUSION: Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT.

Personalized cardiac resynchronization therapy guided by real-time electrocardiographic imaging for patients with non-left bundle branch block.

BACKGROUND: Patients with heart failure and a non-left bundle branch block (non-LBBB) QRS pattern have a limited response to biventricular pacing (BVP). OBJECTIVE: A personalized cardiac resynchronization therapy (CRT) implantation approach guided by real-time electrocardiographic imaging (ECGi) was studied. METHODS: Twenty patients with left ventricular ejection fraction (LVEF) ≤ 35%, QRS duration ≥ 120 ms, and non-LBBB [13 (65%) with right bundle branch block and 7 (35%) with intraventricular conduction delay] were recruited. During CRT implantation, right atrial, right ventricular, coronary sinus, His-bundle, and/or left bundle leads were inserted. The total activation time (TAT) with different pacing combinations were measured in real time during implantation by ECGi. The configuration producing the shortest TAT was chosen. Clinical response was defined as ≥1 New York Heart Association class improvement. Echocardiographic response was defined as left ventricular end-systolic volume reduction ≥ 15% and/or LVEF improvement ≥ 10% at 6 months. RESULTS: After ECGi-guided CRT implantation, LVEF improved from 26% ± 6% to 34% ± 11% (P < .01) and New York Heart Association class improved from 3.0 ± 0.5 to 2.0 ± 0.6 (P < .01). Both clinical and echocardiographic response rates were 70%. The ECGi approach resulted in better acute electrical resynchronization over BVP as measured by TAT reduction (40% vs 14%; P < .01). The percentage of TAT reduction was found to be a strong predictor for echocardiographic response (area under the curve for the receiver operating characteristic curve 0.91; 95% confidence interval 0.78-1.00). A strong positive correlation between percentage TAT reduction and percentage LVEF improvement (Pearson R = 0.70; P = .001) was found. CONCLUSION: ECGi-guided CRT implantation in patients with non-LBBB generates superior acute electrical resynchronization compared with BVP and is associated with favorable clinical and echocardiographic outcomes.

Automatic algorithmic driven monitoring of atrioventricular nodal re-entrant tachycardia ablation to improve procedural safety.

Background: During slow pathway modification for atrioventricular nodal reentrant tachycardia, heart block may occur if ablation cannot be stopped in time in response to high risk electrogram features (HREF). Objectives: To develop an automatic algorithm to monitor HREF and terminate ablation earlier than human reaction. Methods: Digital electrogram data from 332 ablation runs from February 2020 to June 2022 were included. They were divided into training and validation sets which contained 126 and 206 ablation runs respectively. HREF in training set was measured. Then a program was developed with cutoff values decided from training set to capture all these HREF. Simulation ablation videos were rendered using validation set electrogram data. The videos were played to three independent electrophysiologists who each determined when to stop ablation. Timing of ablation termination, sensitivity, and specificity were compared between human and program. Results: Reasons for ablation termination in the training set include short AA time, short VV time, AV block and VA block. Cutoffs for the program were set to maximize program sensitivity. Sensitivity and specificity for the program in the validation set were 95.2% and 91.1% respectively, which were comparable to that of human performance at 93.5% and 95.4%. If HREF were recognized by both human and program, ablations were terminated earlier by the program 90.2% of times, by a median of 574 ms (interquartile range 412-807 ms, p < 0.001). Conclusion: Algorithmic-driven monitoring of slow pathway modification can supplement human judgement to improve ablation safety.

Managing chronic pain in older people.

Management of pain in older people should follow the biopsychosocial model, addressing the heterogeneity in their physiological changes, psychological and cognitive aspects, and impact on their social interactions. When deciding on pharmacological treatment, special attention should be given to the side effect profile, drug-drug and drug-disease interactions, as well as route and timing of medication administration. The principle of 'start low, go slow' should be followed, and regular reviews of drug effectiveness and tolerability are required. With the adjunct of non-pharmacological interventions, the treatment plan should be tailored to individual needs, with the aim to ameliorate the burden of pain while preserving quality of life.

Improvement of long-term survival by cardiac contractility modulation in heart failure patients: A case-control study.

INTRODUCTION: Cardiac contractility modulation (CCM) has been shown to be effective in improving symptoms and cardiac function in heart failure (HF). However, there is limited data on the role of CCM on long-term survival, which was explored in the present study. METHODOLOGY: Forty-one consecutive HF patients with left ventricular ejection fraction (EF) <40% received CCM and were followed for approximately 6 years. They were compared with another 41 HF patients who were enrolled into the HF registry in the same period, and had similar age, gender, EF and etiology of HF. The primary end-point was all cause-mortality. This was stratified by EF. Secondary end-points included HF hospitalization, cardiovascular death, and the composite outcome of death or heart failure hospitalization. RESULTS: The CCM and control groups were well balanced for demographic data, medications and baseline left ventricular EF (27 ± 6 vs 27 ± 7%, p=NS). The mean follow-up duration was 75 ± 19 months in the CCM group and 69 ± 17 months in the control group. All-cause mortality was lower in the CCM group than the control group (39% vs. 71%, respectively; Log-rank χ(2)=11.23, p=0.001). Of note, the improvement of all-cause mortality is more dramatic in patients with EF ≥ 25-40% (36% vs. 80%, Log-rank χ(2)=15.8, p<0.001) than those with EF<25% (50% vs. 56%, p=NS), CCM vs. control respectively. Similar results were shown for the benefit of CCM in the secondary endpoints of cardiovascular death, and the composite outcome of death or heart failure hospitalization. The occurrence of HF hospitalization showed no significant difference between CCM and control groups in the whole cohort (41% vs. 49%, p=NS), but was significantly lower with CCM in subjects with EF ≥ 25-40% at baseline (36% vs. 64%, Log-rank χ(2)=7.79, p=0.005). CONCLUSION: CCM resulted in significant improvement of long-term survival, in particular in those with EF ≥ 25-40%. A reduction in heart failure hospitalizations was also seen in this group of patients with less severely reduced EF.

First clinical experience of the safety and feasibility of total subcutaneous implantable defibrillator in an Asian population.

AIMS: The safety and feasibility of a subcutaneous implantable cardioverter-defibrillator (S-ICD) has been demonstrated in the treatment of life-threatening ventricular tachyarrhythmias (VT). Nonetheless, its safety and feasibility in an Asian population with smaller body-build is unclear. METHODS AND RESULTS: Twenty-one Asian patients who underwent S-ICD from 1 April 2014 to 2 February 2015 in five institutions in Hong Kong and Singapore were retrospectively reviewed. Twenty-one patients with a mean age of 50.0 ± 14.1 years (range 29-77 years, 82.6% male) were included. Among them, 17 (81.0%) were Chinese, 3 (14.3%) were Malay, and 1 (4.8%) was Indian. Their mean body mass index was 23.0 ± 4.0 kg/m(2). An S-ICD was implanted for primary and secondary prevention in 13 (61.9%) and 8 (38.1%) patients, respectively. The indications included Brugada syndrome (n = 6, 28.6%), ischaemic cardiomyopathy (CMP, n = 6, 28.6%), dilated CMP (n = 4, 19.0%), hypertrophic CMP (n = 2, 9.5%), and idiopathic ventricular fibrillation (n = 2, 9.5%). Three patients (14.3%) had prior infected transvenous ICD. There were no acute complications but eight wound complications (persistent wound bleeding requiring intervention = 2; delayed wound healing: upper sternal wound = 3; generator site = 1; local wound infection = 2) were observed in six (28.2%) patients. After a mean follow-up of 107.2 ± 81.3 days (range of 14-254 days), one patient underwent three successful appropriate shocks for treatment of VTs. No inappropriate therapy was documented. CONCLUSION: Our initial experience shows that S-ICD is a feasible treatment for VT among an Asian population with smaller body-build. There was nonetheless a relatively high rate of wound complications.

Comparison of left ventricular reverse remodeling induced by cardiac contractility modulation and cardiac resynchronization therapy in heart failure patients with different QRS durations.

BACKGROUND: Cardiac contractility modulation (CCM) is a new device-based therapy for advanced systolic heart failure with normal QRS duration and therefore not suitable for cardiac resynchronization therapy (CRT). Left ventricular (LV) reverse remodeling was reported in patients treated with CCM or CRT, however, the extent of response was not compared. METHODS: This observational study consisted of three groups of patients with symptomatic heart failure and LV ejection fraction <35% despite optimal medical therapy. Group 1 included those received CCM with a QRS duration <120 ms (n=33), Group 2 included those received CRT with a QRS duration of 120-150 ms (n=43), and Group 3 included those received CRT with a QRS duration >150 ms (n=56). LV end-systolic volume (LVESV) was measured at baseline and 3 months later. RESULTS: Age, gender, etiology of heart failure and baseline ejection fraction were comparable. A significant LV reverse remodeling was observed in each group. The degree of LVESV reduction was similar between Group 1 and Group 2 (-11.3 ± 1 1.8 vs. -13.6 ± 18.3%, p=0.833), however, it was greater in Group 3 (-25.0 ± 18.0%, both p<0.01). By using the reduction ≥ 15%, the responder rate was not different between Group 1 (39%) and Group 2 (42%), but significantly higher in Group 3 (68%) (χ(2)=9.514, p=0.009). CONCLUSION: CCM exhibited a similar LV reverse remodeling response to CRT for patients with a mildly prolonged QRS, though the effect was less strong when compared to CRT for patients with a very wide QRS.

Albumin levels predict survival in patients with heart failure and preserved ejection fraction.

AIMS: Low serum albumin is common in patients with systolic heart failure and is associated with increased mortality. However, the relationship between albumin and outcome in patients with heart failure and preserved ejection fraction (HFPEF) is not known. The aim of this study was to investigate the effect of serum albumin level on survival in patients with HFPEF. METHODS AND RESULTS: We studied 576 consecutive HFPEF patients (left ventricular ejection fraction ≥50%) admitted to our hospital from 2006 to 2009. Standard demographics, transthoracic echocardiography, and routine blood testing including albumin levels were obtained shortly after admission. Outcome was assessed at 1 year after admission. Hypoalbuminaemia (≤34 g/L) was detected in 160 (28%) at admission; and all patients were then divided into hypoalbuminaemia and non-hypoalbuminaemia groups. In the hypoalbuminaemia group, the prevalence of chronic renal failure history, serum creatinine, and urea nitrogen levels were higher when compared with those without hypoalbuminaemia (all P < 0.05). Kaplan-Meier analysis showed that patients with hypoalbuminaemia had a significantly lower survival rate (53% vs. 84%, log-rank χ(2) = 53.3, P < 0.001) and a higher rate of cardiovascular death (21.8% vs. 8.9%, log-rank χ(2) = 19.7, P < 0.001) when compared with those without hypoalbuminaemia. Cox regression further revealed that hypoalbuminaemia, a history of cerebrovascular disease, and older age were the most powerful independent predictors of all-cause mortality in HFPEF patients at 1 year. CONCLUSIONS: Hypoalbuminaemia is common in HFPEF patients and is associated with increased risk of death. Renal dysfunction may be the main pathophysiological mechanism underlying hypoalbuminaemia in HFPEF patients.

Quality of life after percutaneous coronary intervention in the elderly with acute coronary syndrome.

BACKGROUND: Health-related quality of life (HRQoL) is an important but often neglected outcome measure in acute coronary syndrome (ACS) management. The prevalence of elderly presenting with ACS and undergoing percutaneous coronary intervention (PCI) is rising. We aimed to explore the impact of PCI on health status in elderly ACS patients. METHODS: We prospectively enrolled 624 patients admitted to our institution with ACS from February 2006 to May 2008. Short Form (SF)-36 health survey was used to assess HRQoL at baseline and 6 months. Baseline characteristics and HRQoL were compared for patients treated with PCI within 30 days of index ACS admission vs. medical therapy across 3 age groups (<60, 60-79 and ≥80 years). RESULTS: PCI was performed in 73.6%, 55.7% and 21.3% in patients aged <60, 60-79 and older than 80 years, respectively (p<0.01). Elderly patients were more likely to be female (16.9 vs. 35.4 vs. 54.6%, p<0.01) and had more co-morbidities (p<0.01). Older patients were less likely to undergo angiography (84.8 vs. 65.2 vs. 24.8%, p<0.01). Baseline HRQoL decreased with advancing age (p<0.01). However, elderly patients who underwent PCI experienced the most improvement in physical health than younger age groups. PCI was an independent predictor (Odds Ratio = 1.79, 95% CI: 1.10-2.92) of better physical health status at 6 months. CONCLUSION: Elderly ACS patients who underwent PCI experienced the most improvement in physical health compared to younger patients. Our findings suggest that age per se should not deter against revascularization because of potential benefits in HRQOL.

The value of admission HbA(1c) level in diabetic patients with acute coronary syndrome.

BACKGROUND: Elevated admission glucose level is a strong predictor of short-term adverse outcome in patients with acute coronary syndrome (ACS). However, the prognostic value of diabetic control (ie, hemoglobin A(1c) levels) in patients with ACS is still undefined. HYPOTHESIS: Hemoglobin A(1c) level may predict short-term outcome in patients with ACS. METHODS: We conducted a retrospective study with prospective follow-up in 317 diabetic patients with ACS. Patients were stratified into 2 groups based on HbA(1c) level, checked within 8 weeks of the index admission (optimal control group, HbA(1c) ≤7%; suboptimal control group, HbA(1c) >7%). All patients were followed up prospectively for major adverse cardiovascular events (MACE) and mortality for 6 months. Short-term clinical outcomes were also compared between the 2 study groups. RESULTS: In our cohort, 27.4%, 46.4%, and 26.2% patients had unstable angina, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction, respectively. In-hospital mortality was similar in both HbA(1c) groups (3.37% vs 2.88%, P = 0.803). Six-month MACE was also similar (26.40% vs 26.47%, P = 0.919). All-cause mortality, cardiovascular mortality, symptom-driven revascularization, rehospitalization for angina, and hospitalization for heart failure were also similar in both groups. The hazard ratios for 6-month MACE and individual endpoints were also similar in both groups. CONCLUSIONS: This study suggests that HbA(1c) levels before admission are not associated with short-term cardiovascular outcome in diabetic patients subsequently admitted with ACS.

Inadvertent electrical isolation of the left atrial appendage during catheter ablation of persistent atrial fibrillation.

BACKGROUND: Left atrial appendage (LAA) isolation is rare and may be associated with impaired transport function and thromboembolism. OBJECTIVE: The purpose of this study was to determine the mechanisms of inadvertent isolation of the LAA during atrial fibrillation (AF) ablation. METHODS: This study consisted of 11 patients (ejection fraction 0.43 +/- 0.18, left atrial diameter 51 +/- 8 mm) with persistent AF who had LAA conduction block during a procedure for AF (n = 8) or atrial tachycardia (AT) (n = 3). RESULTS: LAA conduction block occurred during ablation at the Bachmann bundle region in 6 patients, mitral isthmus in 3, LAA base in 2, and coronary sinus in 1. The mean distance from the ablation site to the LAA base was 5.0 +/- 1.9 cm. LAA isolation was transient in all 6 patients in whom LAA conduction was monitored and was permanent in the 4 patients in whom conduction was not monitored during energy delivery. The remaining patient was noted to have LAA isolation during a redo procedure before any ablation. Nine of (82%) the 11 patients have remained arrhythmia-free without antiarrhythmic drugs at mean follow-up of 6 +/- 7 months, and all have continued taking warfarin. CONCLUSION: Electrical isolation of the LAA may occur during ablation of persistent AF and AT even when the ablation site is remote from the LAA. This likely is due to disruption of the Bachmann bundle and its leftward extension, which courses along the anterior left atrium and bifurcates to surround the LAA. Monitoring of LAA conduction during ablation of persistent AF or AT is important in avoiding permanent LAA isolation.

Relation of left ventricular systolic dyssynchrony in patients with heart failure to left ventricular ejection fraction and to QRS duration.

Left ventricular (LV) systolic dyssynchrony is an important pathologic mechanism in patients with heart failure (HF). However, the prevalence of intraventricular dyssynchrony in patients with different LV ejection fractions (EFs) is unknown. This study evaluated 402 consecutive patients with HF (mean age 64.99 +/- 13.15 years, 72.4% men) and 120 healthy controls. Dyssynchrony indexes included the SD of the time to peak systolic velocity (Ts) in ejection phase in the 12-segmental model (Ts-SD) and the difference in Ts between basal septal and basal lateral segments (Ts-Septal-Lateral) using tissue Doppler imaging. Patients were divided into 3 groups according to LVEF (LVEF <20%, >20% to 35%, and >35% to 50%) and compared with healthy controls. Both indexes were significantly higher in all 3 LVEF groups compared with controls (p <0.0001). Based on the established cut-off values, systolic dyssynchrony was equally prevalent in all 3 LVEF groups and was 67%, 62%, and 55% using Ts-SD and 38%, 36%, and 35% using Ts-Septal-Lateral, respectively. However, the prevalence of systolic dyssynchrony was higher using Ts-SD than Ts-Septal-Lateral (chi-square = 94.43, p <0.001). Conversely, the prevalence of electrical dyssynchrony, defined as a >120-ms QRS duration, decreased significantly with increasing LVEF (44%, 35%, and 16%; chi-square 5.60, p <0.001). In conclusion, the prevalence of mechanical systolic dyssynchrony was independent of severity of LV systolic dysfunction. This may implicate the potential role of cardiac resynchronization therapy for those with LVEF of 35% to 50%, in particular when systolic dyssynchrony is present.