Impact of ablation index settings on pulmonary vein reconnection.

PURPOSE: Ablation index (AI) is a radiofrequency lesion quality marker. The AI value that allows effective and safe pulmonary vein isolation (PVI) is still debated. We evaluated the incidence of acute and late PV reconnection (PVR) with different AI settings and its predictors. METHODS: The Ablation Index Registry is a multicenter study that included patients with paroxysmal/persistent atrial fibrillation (AF) who underwent first-time ablation. Each operator performed the ablation using his preferred ablation catheter (ThermoCool® SmartTouch or Surround Flow) and AI setting (380 posterior-500 anterior and 330 posterior-450 anterior). We divided the study population into two groups according to the AI setting used: group 1 (330-450) and group 2 (380-500). Incidence of acute PVR was validated within 30 min after PVI, whereas the incidence of late PVR was evaluated at repeat procedure. RESULTS: Overall, 490 patients were divided into groups 1 (258) and 2 (232). There was no significant difference in the procedural time, fluoroscopy time, and rate of the first-pass PVI between the two study groups. Acute PVR was observed in 5.6% PVs. The rate of acute PVR was slightly higher in group 2 (64/943, 6.8%, PVs) than in group 1 (48/1045, 4.6% PVs, p = 0.04). Thirty patients (6%) underwent a repeat procedure and late PVR was observed in 57/116 (49%) PVs (number of reconnected PV per patient of 1.9 ± 1.6). A similar rate of late PVR was found in the two study groups. No predictors of acute and late PVR were found. CONCLUSION: Ablation with a lower range of AI is highly effective and is not associated with a higher rate of acute and late PVR. No predictors of PV reconnection were found.

Predictors of type 2 diabetes relapse after Roux-en-Y Gastric Bypass: A ten-year follow-up study.

AIMS: To assess the impact of bariatric surgery on remission and relapse of type 2 diabetes mellitus (T2DM) at 10 years of follow-up and analyze predictive factors. MATERIALS AND METHODS: Eighty-eight obese subjects undergoing Roux-en-Y gastric bypass (RYGB) and 25 subjects assigned to medical therapy (MT) were evaluated every year for 10 years. T2DM remission was defined by the American Diabetes Association criteria. RESULTS: Body mass index (BMI), fasting glucose, and haemoglobin A1c (HbA1c) improved more markedly in RYGB than MT patients throughout the 10-year period. Post-surgery remission rates were 74% and 53% at 1 and 10 years, respectively, while remission did not occur in MT patients. One-year post-surgery, BMI decreased more in subjects with remission than in those without, but no further decrease was observed thereafter. By partial-least-squares analysis, T2DM duration, baseline HbA1c, and ensuing insulin therapy were the strongest predictors of remission. Remission was achieved at one year in 91% of patients with T2DM duration < 4 years, and 79% of them remained in remission at 10 years. On the contrary only 42% of patients with T2DM duration ≥ 4 years achieved remission, which was maintained only in 6% at the end of 10 years. By survival analysis, patients with T2DM duration < 4 years had higher remission rates than those with duration ≥ 4 years (hazards ratio (HR) 3.1 [95%CI 1.8-5.7]). Relapse did not occur before two years post-surgery and was much less frequent in patients with < 4- vs ≥ 4-year duration (HR 11.8 [4.9-29.4]). CONCLUSIONS: Short T2DM duration and good glycemic control before RYGB surgery were the best requisites for a long-lasting T2DM remission, whereas weight loss had no impact on the long-term relapse of T2DM.

Cerebral hemodynamics during atrial fibrillation: Computational fluid dynamics analysis of lenticulostriate arteries using 7 T high-resolution magnetic resonance imaging.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, inducing irregular and faster heart beating. Aside from disabling symptoms-such as palpitations, chest discomfort, and reduced exercise capacity-there is growing evidence that AF increases the risk of dementia and cognitive decline, even in the absence of clinical strokes. Among the possible mechanisms, the alteration of deep cerebral hemodynamics during AF is one of the most fascinating and least investigated hypotheses. Lenticulostriate arteries (LSAs)-small perforating arteries perpendicularly departing from the anterior and middle cerebral arteries and supplying blood flow to basal ganglia-are especially involved in silent strokes and cerebral small vessel diseases, which are considered among the main vascular drivers of dementia. We propose for the first time a computational fluid dynamics analysis to investigate the AF effects on the LSAs hemodynamics by using 7 T high-resolution magnetic resonance imaging (MRI). We explored different heart rates (HRs)-from 50 to 130 bpm-in sinus rhythm and AF, exploiting MRI data from a healthy young male and internal carotid artery data from validated 0D cardiovascular-cerebral modeling as inflow condition. Our results reveal that AF induces a marked reduction of wall shear stress and flow velocity fields. This study suggests that AF at higher HR leads to a more hazardous hemodynamic scenario by increasing the atheromatosis and thrombogenesis risks in the LSAs region.

The prevalence of TTR cardiac amyloidosis among patients undergoing bone scintigraphy.

BACKGROUND: Radiolabeled bisphosphonates bone scintigraphy is highly sensitive in detecting transthyretin (TTR) cardiac amyloidosis; data on the true prevalence of cardiac involvement in TTR amyloidosis are lacking. METHODS AND RESULTS: This retrospective observational, monocentric study aims to estimate the prevalence of positive bone scan suspect for TTR cardiac amyloidosis among an all-comers population who underwent a bone scintigraphy. ECG, echocardiography and clinical status of patients with unexpected cardiac uptake (Perugini score 2-3) who underwent bone scintigraphy with [99mTc]-HDP or [99mTc]-DPD at San Luigi Gonzaga University Hospital between January 2015 and May 2020 have been collected. The prevalence of bone scintigraphy suspect for cardiac involvement was 0.54% (23/4,228). The bone scintigraphy was mainly performed using [99mTc]-HDP (82.9%) and the dominant indication for the test was oncology in the 47.9% of cases. 8 Subjects had a history of neuropathy (34.8%) and 5 of carpal tunnel syndrome (21.7%). 11 Patients suffered a previous episode of heart failure (48%) while 5 patients (21.7%) were totally asymptomatic, without any sign or symptom before the bone scintigraphy making the nuclear examination crucial for an early diagnosis of TTR amyloidosis. CONCLUSION: Bone scintigraphy allows suspecting TTR amyloidosis in a pre-clinical stage of the disease in an all-comers population of patients undergoing bone scintigraphy mainly for oncology reasons.

Impaired coronary blood flow at higher heart rates during atrial fibrillation: Investigation via multiscale modelling.

BACKGROUND: Different mechanisms have been proposed to relate atrial fibrillation (AF) and coronary flow impairment, even in absence of relevant coronary artery disease (CAD). However, the underlying hemodynamics remains unclear. Aim of the present work is to computationally explore whether and to what extent ventricular rate during AF affects the coronary perfusion. METHODS: AF is simulated at different ventricular rates (50, 70, 90, 110, 130 bpm) through a 0D-1D multiscale validated model, which combines the left heart-arterial tree together with the coronary circulation. Artificially-built RR stochastic extraction mimics the in vivo beating features. All the hemodynamic parameters computed are based on the left anterior descending (LAD) artery and account for the waveform, amplitude and perfusion of the coronary blood flow. RESULTS: Alterations of the coronary hemodynamics are found to be associated either to the heart rate increase, which strongly modifies waveform and amplitude of the LAD flow rate, and to the beat-to-beat variability. The latter is overall amplified in the coronary circulation as HR grows, even though the input RR variability is kept constant at all HRs. CONCLUSIONS: Higher ventricular rate during AF exerts an overall coronary blood flow impairment and imbalance of the myocardial oxygen supply-demand ratio. The combined increase of heart rate and higher AF-induced hemodynamic variability lead to a coronary perfusion impairment exceeding 90-110 bpm in AF. Moreover, it is found that coronary perfusion pressure (CPP) is no longer a good measure of the myocardial perfusion for HR higher than 90 bpm.

Catheter ablation in atrial fibrillation: is there a mortality benefit in patients with diabetes and heart failure?

Atrial fibrillation (AF) is the most commonly sustained arrhythmia, and patients with diabetes mellitus (DM) exhibit an increased incidence of AF. Besides DM, heart failure (HF) shares pathophysiological links with AF, mainly related to the pathological remodeling of hearts affected by structural disease. As in a vicious circle, AF may contribute to HF worsening and increased mortality in patients with structural heart diseases, and the outcome may be further impaired when concomitant DM is present. Although no data directly referring to DM patients with HF are available, indirect information can be drawn from large studies on patients with HF and AF. The present review discusses the outcome of AF ablation in patients with DM and HF, focusing on safety, efficacy, and most particularly on hard endpoints such as mortality and thromboembolic event incidence.

Implanted Closed-Loop Gastric Electrical Stimulation (CLGES) System with Sensor-Based Feedback Safely Limits Weight Regain at 24 Months.

BACKGROUND: Weight regain following bariatric surgery is not uncommon. Safe, effective weight loss treatment up to 1 year has been reported with the closed-loop gastric electrical stimulation (CLGES) system. Continuous recording of eating and activity behavior by onboard sensors is one of the novel features of this closed-loop electrical stimulation therapy, and may provide improved long-term weight maintenance by enhancing aftercare. METHODS: Four centers participating in a 12-month prospective multicenter randomized study monitored all implanted participants (n = 47) up to 24 months after laparoscopic implantation of a CLGES system. Weight loss, safety, quality of life (QOL), and cardiac risk factors were analyzed. RESULTS: Weight regain was limited in the 35 (74%) participants remaining enrolled at 24 months. Mean percent total body weight loss (%TBWL) changed by only 1.5% between 12 and 24 months, reported at 14.8% (95% CI 12.3 to 17.3) and 13.3% (95% CI 10.7 to 15.8), respectively. The only serious device-/procedure-related adverse events were two elective system replacements due to lead failure in the first 12 months, while improvements in QOL and cardiovascular risk factors were stable thru 24 months. CONCLUSION: During the 24 month follow-up, CLGES was shown to limit weight regain with strong safety outcomes, including no serious adverse events in the second year. We hypothesize that CLGES and objective sensor-based behavior data combined to produce behavior change. The study supports CLGES as a safe obesity treatment with potential for long-term health benefits. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01448785.

Alteration of cerebrovascular haemodynamic patterns due to atrial fibrillation: an in silico investigation.

There has recently been growing evidence that atrial fibrillation (AF), the most common cardiac arrhythmia, is independently associated with the risk of dementia. This represents a very recent frontier with high social impact for the number of individuals involved and for the expected increase in AF incidence in the next 40 years. Although a number of potential haemodynamic processes, such as microembolisms, altered cerebral blood flow, hypoperfusion and microbleeds, arise as connecting links between the two pathologies, the causal mechanisms are far from clear. An in silico approach is proposed that combines in sequence two lumped-parameter schemes, for the cardiovascular system and the cerebral circulation. The systemic arterial pressure is obtained from the cardiovascular system and used as the input for the cerebral circulation, with the aim of studying the role of AF on the cerebral haemodynamics with respect to normal sinus rhythm (NSR), over a 5000 beat recording. In particular, the alteration of the haemodynamic (pressure and flow rate) patterns in the microcirculation during AF is analysed by means of different statistical tools, from correlation coefficients to autocorrelation functions, crossing times, extreme values analysis and multivariate linear regression models. A remarkable signal alteration, such as a reduction in signal correlation (NSR, about 3 s; AF, less than 1 s) and increased probability (up to three to four times higher in AF than in NSR) of extreme value events, emerges for the peripheral brain circulation. The described scenario offers a number of plausible cause-effect mechanisms that might explain the occurrence of critical events and the haemodynamic links relating to AF and dementia.

Closed-loop gastric electrical stimulation versus laparoscopic adjustable gastric band for the treatment of obesity: a randomized 12-month multicenter study.

OBJECTIVE: To compare the weight loss, change in quality of life (QOL) and safety of closed-loop gastric electrical stimulation (CLGES) versus adjustable gastric band (LAGB) in the treatment of obesity. METHODS: This multicenter, randomized, non-inferiority trial randomly assigned the patients in a 2:1 ratio to laparoscopic CLGES versus LAGB and followed them for 1 year. We enrolled 210 patients, of whom 50 were withdrawn preoperatively. Among 160 remaining patients (mean age=39±11 years; 75% women; mean body mass index=43±6 kg m-2) 106 received CLGES and 54 received LAGB. The first primary end point was non-inferiority of CLGES versus LAGB, ascertained by the proportion of patients who, at 1 year, fulfilled: (a) a ⩾20% excess weight loss (EWL); (b) no major device- or procedure-related adverse event (AE); and (c) no major, adverse change in QOL. Furthermore, ⩾50% of patients had to reach ⩾25% EWL. The incidence and seriousness of all AE were analyzed and compared using Mann-Whitney's U-test. RESULTS: At 1 year, the proportions of patients who reached all components of the primary study end point were 66.7 and 73.0% for the LAGB and CLGES group, respectively, with a difference of -6.3% and an upper 95% CI of 7.2%, less than the predetermined 10% margin for confirming the non-inferiority of CLGES. The second primary end point was also met, as 61.3% of patients in the CLGES group reached ⩾25% EWL (lower 95% CI=52.0%; P<0.01). QOL improved significantly and similarly in both groups. AE were significantly fewer and less severe in the CLGES than in the LAGB group (P<0.001). CONCLUSIONS AND RELEVANCE: This randomized study confirmed the non-inferiority of CLGES compared with LAGB based on the predetermined composite end point. CLGES was associated with significantly fewer major AE.