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ObjectiveTo evaluate the size and depth of linear lesions by in vitro testing with a custom-made radio frequency biparietal bipolar ablation catheter in a single-stage setting.MethodsA custom-made catheter was created to generate linear lesions around the left atrium and pulmonary veins of an ex vivo pig. Two frames were made, 1 epicardial and 1 endocardial. A continuous copper braid electrode and an alignment system consisting of 2 parallel rows of neodymium magnets were embedded in a flexible plastic support. After 24 hours of formalin conservation, samples of the left atrium of a freshly slaughtered pig were sliced in a cryotome, thus obtaining a sequence of 100-µm thick layers extending from the endocardial to the epicardial side. After being digitized through a scanner, these layers were evaluated using morphometric computer software. For each slice, we evaluated the maximum length of the lesions, the maximum epicardial length, the maximum endocardial length, the total area of the lesion, and the total volume.ResultsForty transmural lesions from 40 specimens were obtained. The results were the following (the number in parenthesis is the interquartile range in mm): lesion maximum length ( LMAX) was 7.297 mm (0.006), epicardial maximum length ( LEPI) was 7.291 mm (0.014), and endocardial maximum length was 7.291 mm (0.018). The total area and total volume were 1018.50 ± 36.51 mm2and 101.85 ± 3.65 mm3, respectively.ConclusionsOur prototype showed very promising results. The next step will be to enhance the design for clinical application.

Background and aim Classical and paradoxical low‐flow, low‐gradient (LFLG) aortic stenosis (AS) are the most challenging subtypes of AS. The current therapeutic options are aortic valve replacement (AVR) and conservative management: AVR promotes long‐term survival but is invasive, while conservative management yields a poor prognosis but is noninvasive since it uses no aortic valve replacement (noAVR). The present meta‐analysis investigated the rate of survival of patients with LFLG AS undergoing either AVR or noAVR interventions. Methods The meta‐analysis compared the outcomes of AVR with those of noAVR in terms of patient survival. In both groups, a meta‐regression was conducted to investigate the impact on patient survival of the left ventricular ejection fraction (LVEF), either preserved (paradoxical LFLG AS) or reduced (classical LFLG AS). Results The relative risk of survival between the AVR and noAVR groups was 1.99 [1.40, 2.82] (p = .0001), suggesting that survival tends to be better in AVR patients than in noAVR patients. The meta‐regression revealed that a reduced LVEF may be related to a higher survival in AVR patients when compared to a preserved LVEF (p = .04). Finally, the analysis indicated that LVEF seems not to be prognostic of survival in noAVR patients (p = .18). Conclusions Patients with LFLG AS have better survival if they undergo AVR. In AVR patients, reduced LVEF rather than preserved LVEF is related to better survival, whereas there seems to be no difference in prognostic value between reduced and preserved LVEF in noAVR patients.

The aim was to use a propensity score-based analysis to determine the impact of peripheral artery disease (PAD) on early outcomes after coronary artery bypass surgery grafting (CABG) in patients with PAD.We conducted a multicentre retrospective analysis of 11,311 consecutive patients who underwent CABG between 1997 and 2017. Patients with previous or concomitant vascular surgery were excluded. The main endpoints were death, stroke, and limb ischaemia requiring percutaneous or surgical revascularisation. Subgroup analyses were performed to test the interaction of PAD with concomitant factors.There was no difference in mortality in patients with and without PAD (p=0.06 and p=0.179, respectively). Patients with PAD had a greater incidence of stroke (p=0.04), acute kidney disease (p=0.003), and limb ischaemia requiring interventions (p0.001) than those without PAD. The use of off-pump or no-touch aortic techniques did not influence the effect of PAD on the outcomes. Early mortality rate increased in patients with PAD when associated with long cardiopulmonary bypass, cross-clamp times (both p0.001), and postoperative low cardiac output (p=0.01).The presence of PAD is associated, independently of other factors, with greater incidence of stroke, acute kidney disease, and limb ischaemia following CABG, irrespective of the technique employed. Operative mortality was greater in patients with PAD only when associated with long cardiopulmonary bypass and aortic cross-clamp times, and low cardiac output.

Purpose To make an in vitro evaluation of the lesion size and depth produced in two different sets of radio frequency energy bipolar delivery: simultaneous biparietal bipolar (SBB) and simultaneous uniparietal bipolar (SUB). Methods Two separate prototypes have been built for our purpose: one to be used in SBB mode and the other to be used SUB mode. Forty left atrium samples were taken from the hearts of freshly slaughtered pigs. They were ablated into a simulator ABLABOX, where blood flow, temperature, and contact force were controlled. After being sliced into a cryotome, the samples were digitalized by a flatbed scanner, and the images were analyzed by a computer morphometric software. Results Transmural lesions were achieved in 18/20 samples (90%) in SBB, while SUB showed transmurality in 9/20 samples (45%). Overall maximum diameter (DMAX) resulted larger in SUB than in SBB (2.43 ± 0.30 mm, 1.62 ± 0.14 mm, respectively; p DEPI and DENDO, respectively) were wider in SUB group than SBB group (2.28 ± 0.30 mm, 2.26 ± 0.40 and 1.60 ± 0.14 mm, 1.59 ± 0.15 mm, respectively; p ATOT and VTOT) were broader in SUB group than in SBB one (581.01 ± 65.38 mm/mm2, 58.10 ± 6.53 mm/mm3 and 521.97 ± 73.05 mm/mm2, 52.19 ± 7.30 mm/mm3. respectively; p Conclusions In contrast with the smaller lesion sizes, the biparietal bipolar group showed a higher transmurality rate. These findings may suggest a better drive of the energy flow when compared with SUB lesions.

Objective To compare lesion size and depth between a 1-step, a sequential, and a delayed radio-frequency ablation in a hybrid setup. Methods Left atrium tissues obtained from fresh porcine hearts were mounted into the ABLABOX simulator. Based on the time differences between the index epicardial (epi) and consequent endocardial (endo) ablation, 3 study groups were compared: a 1-stage (SEQ- 0) group (0-minute delay), an SEQ 1 group (60-minute delay), and an SEQ 2 group (240-minute delay). During the experiment, a constant epicardial (300 gr) and endocardial (30 gr) force were applied. Per group, 20 samples were studied, and the resulting lesion size and depth were quantified with morphometric evaluation. Results Overall, no transmural lesion was obtained. Lesions in SEQ 0 had better maximum and minimum diameters ( P < 0.001), a larger total area ( P < 0.001), and volume ( P < 0.001) than SEQ 1 and SEQ 2. There was no statistical difference in morphometric parameters (all, P > 0.05) between the delayed procedures (SEQ 1 and SEQ 2). Conclusions In our in vitro model, different time sequences of combined epi–endo ablation did not result in transmural lesions. However, simultaneous epi–endo ablation produced broader and deeper lesions. Our findings need to be confirmed by further research.

Background We carried out a propensity score-based analysis on early outcomes after coronary artery bypass grafting (CABG) in patients with and without peripheral artery disease (PAD). Materials and Methods A total of 11 311 patients undergoing isolated CABG between 1997 and 2017 were included in the study. Patients were divided into two groups based on whether they were affected (n = 1961) or not affected (n = 9350) by PAD. Inverse probability of treatment weighting was employed to reduce confounding preoperative and operative variables. The main endpoints were death, cardiac death, stroke, and limb ischemia requiring percutaneous or surgical revascularization. Results The excellent balance was obtained, and the groups were very similar. For death and cardiac death, there were no differences between patients with and without PAD (P = .06 and P = .179, respectively). In contrast, PAD patients showed a higher incidence of stroke (P = .04), acute kidney disease (AKD) (P = .003) and limb ischemia requiring intervention (P

The connection between atrial fibrillation (AF) and H. pylori (HP) infection is still matter of debate. We performed a systematic review and metanalysis of studies reporting the association between AF and HF. A systematic review of all available reports in literature of the incidence of HP infection in AF and comparing this incidence with subjects without AF were analysed. Risk ratio and 95% confidence interval (CI) and risk difference with standard error (SE) were the main statistics indexes. Six retrospective studies including a total of 2921 were included at the end of the selection process. Nine hundred-fifty-six patients (32.7%) were in AF, whereas 1965 (67.3%) were in normal sinus rhythm (NSR). Overall, 335 of 956 patients with AF were HP positive (35%), whereas 621 were HP negative (65%). In addition, 643 of 1965 NSR patients (32.7%) were HP positive while 1,322 were negative (67.3%; Chi-square 2.15, p = 0.21). The Cumulative Risk Ratio for AF patients for developing an HP infection was 1.19 (95% CI 1.08–1.41). In addition, a small difference risk towards AF was found (0.11 [SE = 0.04]). Moreover, neither RR nor risk difference were influenced by the geographic area at meta-regression analysis. Finally, there was a weak correlation between AF and HP (coefficient = 0.04 [95% CI −0.01–0.08]). We failed to find any significant correlation between H. pylori infection and AF and, based on our data, it seems unlikely than HP can be considered a risk factor for AF. Further larger research is warranted.

What is the central question of this study? Visceral ischaemia is one of the most feared complications during use of an intra-aortic balloon pump. Using an animal model, we measured the flows at the abdominal level directly and examined flow patterns to enable investigation of flow patterns during the use of the intra-aortic balloon pump. What is the main finding and its importance? We show that there is a significant balloon-related reduction in superior mesenteric flow in both early and mid-diastole.A number of previous studies have shown that blood flow in the visceral arteries is altered during intra-aortic balloon pump (IABP) treatment. We used a porcine model to analyse the pattern of blood flow into the visceral arteries during IABP use. For this purpose, we measured the superior mesenteric, right renal and left renal flows before and during IABP support, using surgically placed flowmeters surrounding these visceral arteries. The superior mesenteric flow significantly decreased in early diastole (P 0.001) and in mid-diastole (P = 0.003 versus early diastole), whereas in late diastole it increased again (P 0.001 versus mid-diastole). During systole, the flow was not significantly increased compared with late diastole (P = 0.51), but it was significantly lower than at baseline (both P 0.001). Flows did not differ between right and left kidneys. Perfusion of either kidney did not change significantly in early diastole (P 0.05), whereas it decreased significantly in mid-diastole (P 0.001), rising dramatically in late diastole (P 0.001) and with an additional slight increase in systole (P = 0.054). This study provides important insights into abdominal flows during intra-aortic pump counterpulsation. Furthermore, it supports the need to rethink the balloon design to avoid visceral ischaemia during circulatory assistance.

OBJECTIVESThe aim of this study was to evaluate the lesion size and depth of radiofrequency (RF) ablation in a simultaneous biparietal bidirectional bipolar (SBB) approach, compared to a simultaneous and staged unipolar and uniparietal bipolar setup [simultaneous uniparietal bipolar (SiUB) and staged uniparietal bipolar (StUB), respectively].METHODSFresh left atrial porcine tissue was mounted into the ABLA-BOX simulator. Different ablation approaches were tested: (i) SBB: a concept consisting of SBB endo-epicardial ablation, (ii) SiUB: simultaneous epicardial uniparietal bipolar and endocardial unipolar ablation and (iii) StUB: staged epicardial uniparietal bipolar and endocardial unipolar ablation. In the StUB setup, a 1-h interval between the epi-endo ablation was respected.RESULTSTransmural lesions were present in 90% of the bipolar biparietal ablations, yet no full transmurality was observed in the simultaneous nor in the staged unipolar with uniparietal bipolar ablation group. In SBB, the area and volume of the ablation lesions were smaller (523.33 mm2/mm and 52.33 mm3/mm, respectively) than in SiUB (588.17 mm2/mm and 58.81 mm3/mm, respectively) and StUB (583.76 mm2/mm and 58.37 mm3/mm, P = 0.044). Also, in SBB, the overall, epicardial and endocardial maximum diameters of the lesions (1.59, 1.57 and 1.52 mm; respectively) were smaller than in SiUB (2.38, 2.26 and 2.33 mm; respectively) and in StUB (2.36, 2.28 and 2.14 mm; respectively, all P CONCLUSIONSAlthough bipolar biparietal bidirectional RF ablation results in smaller lesions than uniparietal bipolar and unipolar ablation, their capacity to penetrate the tissue is much higher. Moreover, in uniparietal RF applications, the energy spreads in the superficial layers of the tissue but fails to penetrate. Therefore, the degree of transmurality is much higher when using such a ‘truly bipolar’ ablation approach.

Introduction: This study aimed to test a computer-driven cardiovascular model for the evaluation of the visceral flow during intra-aortic balloon pump (IABP) assistance. Methods: The model includes a systemic and pulmonary circulation as well as a heart contraction model. The straight polyurethane tube aorta had a single visceral while four windkessel components mimicked resistance compliance of the brachiocephalic, renal and sub-mesenteric, pulmonary, and systemic circulation. Twelve flow probes were placed in the circuit to measure pressures and flows with the IABP on and off. Results: With the balloon off, the meantime to reach the steady state was 48 ± 16 s; with the balloon on, this figure was 178 ± 20 s. The stability of pressure and flow signals was obtained after 72 ± 11 min. The number of cycles of stability of the system was 93 [86–103]. Measurements were reliable either with samples of 10 or 20 beats. Bland Altman method demonstrated the reliability of measurements. Finally, all measurements were comparable to published in vivo data. Conclusion: The presented mock circulation was reliable and gave values with high accuracy both at baseline and during mechanical assistance. This system allows evaluation of the mesenteric flow during IABP, under different clinical/hemodynamic conditions. Nonetheless, its translational potential needs to be further evaluated

Aim: We evaluated the influence of intra-aortic balloon size and volume on mesenteric and renal flows. Methods: Thirty healthy swine underwent 120-minute ligation of the left anterior descending coronary artery followed by 6 hours of reperfusion. Then, they were randomly assigned to the following five groups of animals, with six animals in each group: no intra-aortic balloon pump (IABP), a short 35-mL IABP, a short 40-mL IABP, a long 35-mL IABP and a long 40-mL IABP. Superior mesenteric artery (SMA) and renal flows were measured at baseline (t0), at 2-hour ischemia (t1) and every hour thereafter until 6 hours of reperfusion (from tR1 to tR6). Results: SMA flows increased significantly at tR1 only in the two short IABP groups (p0.05). Renal flows appeared to be influenced by balloon length, but not by volume. Indeed, flows in the renal arteries rose during IABP treatment; the increase was significantly higher in the short balloon groups and throughout the whole reperfusion (all, pConclusions: Changes in visceral perfusion during IABP assistance were significantly related to balloon length, but not to its volume. This could be relevant for the evolution of balloon engineering design in order to reduce the incidence of mesenteric ischemia following IABP. Further research is necessary to confirm these findings.

Background and Aims\ud The main pathophysiological factor of chronic ischemic mitral regurgitation (MR) is the outward displacement of the papillary muscles (PMs) leading to leaflet tethering. For this reason, papillary muscle intervention (PMI) in combination with mitral ring annuloplasty (MRA) has recently been introduced into clinical practice to correct this displacement, and to reduce the recurrence of regurgitation.\ud \ud Methods\ud A meta‐analysis was conducted comparing the outcomes of PMI and MRA performed in combination vs MRA performed alone, in terms of MR recurrence and left ventricular reverse remodeling (LVRR). A meta‐regression was carried out to investigate the impact of the type of PMI procedure on the outcomes.\ud \ud Results\ud MR recurrence in patients undergoing both PMI and MRA was lower than in those who only had MRA (log incidence rate ratio, −0.66; lower‐upper limits, −1.13 to 0.20; I2 = 0.0%; p = .44; Egger's test: intercept 0.35 [−0.78 to 1.51]; p = .42).\ud \ud The group with both PMI and MRA and that with only MRA showed a slightly higher reduction in left ventricular diameters (−5.94%; −8.75% to 3.13%,). However, in both groups, LVRR was p = .33).\ud \ud Conclusions\ud Using PMI and MRA together has a lower MR recurrence than using MRA alone. No significant LVRR was observed between the two groups nor between the PMI techniques employed.

Background and Aims We investigated neurological events, graft patency, major adverse cardiovascular events (MACEs), and mortality at 1 year following coronary artery bypass grafting (CABG) surgery using automated proximal anastomotic devices (APADs) and compared the overall rates with the current literature. Methods A systematic review of all available reports of APADs use in the literature was conducted. Cumulative incidence and 95% confidence interval (CI) were the main statistical indexes. Nine observational studies encompassing a total of 718 patients were included at the end of the selection process. Results The cumulative event rate of neurological complications was 4.8% (lower‐upper limits: 2.8‐8.0, P

Background We explore the association between short- and long- term adverse outcomes following coronary artery bypass grafting (CABG) and the degree of preoperative renal dysfunction classified on glomerular fraction estimated with Chronic Kidney Disease-Epidemiology Collaboration equation (eGFR CKD-EPI ). We also try to identify cut-off values of eGFR CKD-EPI able to predict post-CABG unfavorable events and assess whether a reclassification with new thresholds is necessary. Methods One-thousand-one-hundred-eighty-six consecutive patients undergoing CABG between 2005 and 2014 were categorized in 4 groups according to the eGFR CKD-EPI : Group 1 (≥60ml/min/1.73m 2 ; n=1199), Group 2 (45–59ml/min/1.73m 2 ; n=358), Group 3 (30–44ml/min/1.73m 2 ; n=171) and Group 4 (≤29ml/min/1.73m 2 ; n=126). Median follow-up was 66months [IQR 46–84]. Results eGFR CKD-EPI ≤30ml/min/1.73m 2 , ≤41ml/min/1.73m 2 , ≤27ml/min/1.73m 2 and ≤29ml/min/1.73m 2 were strong predictors of early mortality (OR 5.88 [95% CI 2.59–11.25]), stroke (2.59 [1.43–3.71]), prolonged length of stay (3.49 [1.24–5.92]) and postoperative dialysis (3.68 [1.34–4.91]), respectively. In addition, eGFR CKD-EPI ≤26ml/min/1.73m 2 , ≤25ml/min/1.73m 2 , ≤35ml/min/1.73m 2 and ≤29ml/min/1.73m 2 predicted all-cause death (hazard ratio 2.74 [95% CI 2.10–3.92] cardiovascular death (sub-hazard ratio 2.11 [95% CI 1.42–3.90]), myocardial infarction (2.01 [1.32–3.70]) and heart failure (2.24 [1.41–3.93]), respectively. Analyses corrected by age and left ventricular ejection fraction confirmed these findings. Conclusions In our experience, the use of the eGFR CKD-EPI equation led to categorization with a significantly lower number of patients at risk for post-CABG complications. This might have important clinical repercussions on allocation of healthcare resources and more targeted prevention and management of CABG complications.

This proof-of-concept study examined the haemodynamic performance as well as the coronary and visceral organ perfusion using a new short balloon for intra-aortic counterpulsation (IABP) in a swine model of myocardial ischaemia. Eighteen healthy pigs underwent 120-min ligation of the left anterior descending coronary artery followed by 6 h of reperfusion, and they were randomly assigned into 3 groups undergoing IABP implantation with a 35-ml short balloon (n = 6), a 40-ml short balloon (n = 6) or no IABP implantation (controls, n = 6). Haemodynamics, and visceral and coronary flows were measured at baseline (t(0)), at 2 h of ischaemia (t(1)) and every hour thereafter until 6 h of reperfusion (from t(R1) to t(R6)), respectively. Mesenteric and renal flows increased significantly at t(R1) only in the IABP groups (all, P 0.05). The new short balloon significantly increased visceral flow, enhanced haemodynamics and improved coronary circulation during reperfusion following myocardial ischaemia in our experimental model.

Patients with pre-existing cardiovascular disease (CVD) might be more susceptible to infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and have higher mortality rates. Nevertheless, the risk of mortality has not been previously quantified. The aim of this meta-analysis is to quantify the risk of mortality in coronavirus disease 2019 (COVID-19) patients. A meta-analysis was conducted analyzing the impact of (1) sex, (2) age, (3) CVD with coronary artery disease (CAD), (4) CAD alone, (5) CVD without CAD, (6) hypertension, (7) cerebrovascular diseases, and (8) diabetes on mortality. Relative risk was assessed for dichotomous variables, mean difference for continuous variables. Twenty-six studies were included, encompassing 8497 patients. Males had 16% higher risk of mortality than females (p < 0.05) and elderly patients had higher chance of dying than younger patients (p < 0.0001). Patients with overall CVD have a 1.96-fold higher mortality risk (p < 0.0001). CAD increases risk of mortality by 1.90-fold (p < 0.05). CVD-CAD were found to increase risk up to 2.03-fold (p < 0.05). Hypertension, cerebrovascular disease and diabetes increase the risk of death up to 1.73-fold, 1.76-fold and 1.59-fold, respectively (p < 0.0001, p < 0.0001, p < 0.05, respectively). Sex, age, presence of CAD and/or other types of CVD, hypertension, cerebrovascular diseases and diabetes mellitus increase mortality in patients with COVID-19.

Objective Visceral ischemia can be a potentially life-threatening complication of intra-aortic balloon pump (IABP) support. A shorter IABP catheter might lead to a reduction of visceral complications. In this animal study, we evaluate the effects of a 35-mL short catheter in comparison with a 40-mL standard-sized catheter. Methods Eighteen healthy swine underwent 120-minute ligation of the left anterior descending coronary artery followed by 6 hours of reperfusion being supported by either a short IABP catheter (short group) (n = 6) or a long IABP catheter (long group) (n = 6) or with no assistance (controls) (n = 6). Hemodynamics, visceral and coronary flows, as well as biochemical markers were evaluated throughout the different phases of the protocol. Results Mesenteric flows increased significantly at reperfusion (P < 0.001 both) remaining constant afterward (all, P > 0.05) in the short group, while remaining significantly lower in the long group at the start of reperfusion, remaining constantly lower than the short group and controls (P < 0.001 vs short, P < 0.003 vs controls). In both long and short groups, catheters improved renal flows at reperfusion (P < 0.001 both) without any further variation (P < 0.05). In the short group, the flows were higher during the whole of reperfusion (all, P < 0.05). Intra-aortic balloon pump support improved hemodynamic indices and coronary blood flows during reperfusion to a similar extent in both the small and the long group (P > 0.05). Conclusions The short IABP catheter proved to be as effective as the standard-sized catheter in supporting hemodynamics and coronary circulation. Furthermore, it even improves visceral flows in comparison with conventional IABP catheters.

Objective We present the first testing study on the ABLA-BOX, a new in vitro module of hybrid atrial fibrillation ablation. Methods ABLA-BOX consists of two chambers that mimic the epicardial and endocardial sides of the heart. The septum between chambers provides catheter access on both sites of the cardiac tissue. A circuit, filled with freshly obtained porcine blood, including a pump, an oxygenator, and a heating device, circulate the blood inside the system. Left atrial fresh tissue is mounted on a tissue holder and magnetically fixed. Epicardial and endocardial catheters are fixed on the catheter holders and blocked with the locker knob. The system allows control of ablation force, flow rate, temperature, and flow pattern. Results Epicardial contact force of 100 g and endocardial force of 30 g resulted in larger lesion volumes (P < 0.001), areas (P < 0.001), and lesion diameters (P = 0.03 and P = 0.008), than the combination of 100/20 g. In addition, with a flow rate of 5 L/min, lesion volumes (P = 0.02), areas (P < 0.001), and diameters (both, P < 0.001) were significantly larger in comparison with those of 3 L/min. Furthermore, dimensions (both, P < 0.001), volume (P < 0.001), and area (P < 0.001) of the lesions at a circulating blood temperature of 38.0°C were larger than with a lower blood temperature (36.0°C). Finally, ablations made under stable flow pattern resulted in greater lesion diameters P = 0.04 and P = 0.03) as well as larger volumes (P = 0.02) and areas (P = 0.03) than under turbulent-like flow reproduced with the system rotor set to 400 rpm. Conclusions The ABLA-BOX allowed easy hybrid ablation with different setups, which can provide cardiologists and cardiac surgeons with reliable and more valuable insights.

OBJECTIVES: We compare a short and a standard-size balloon with same filling volumes to verify the differences in terms of visceral flow, coronary circulation and haemodynamic performance during aortic counterpulsation in an animal model of myocardial ischaemia-reperfusion injury. METHODS: Eighteen healthy pigs underwent 120-min ligation of the left anterior descending coronary artery followed by 6 h of reperfusion, and they were randomly assigned to have intra-aortic balloon counterpulsation (IABP) with a 40-ml short-balloon (n = 6) or a 40-ml standard-length balloon (n = 6), or to undergo no IABP implantation (controls, n = 6). Haemodynamics and visceral and coronary flows were measured at baseline (t(0)), at 2 h of ischaemia (t(1)) and every hour thereafter until 6 h of reperfusion (from t(R1) to t(R6)), respectively. RESULTS: Mesenteric flows increased significantly at tR1 only in the short-balloon group (P 0.05). CONCLUSIONS: The short balloon prevents visceral ischaemia and, compared with the standard-size balloon, it does not lose IABP beneficial cardiac and coronary-related effects. Further studies are warranted to confirm our findings.

Background. Changes in hemodynamics, coronary circulation, visceral flow, and biochemical marker rate reduction or volume deflation for intraaortic balloon pump discontinuation were assessed. Methods. Twelve healthy pigs were randomly assigned to two groups, the rate-based (RB, n = 6) and volume-based weaning groups (VB, n = 6). Hemodynamics and visceral and coronary flows were measured at baseline after 2 hours of intraaortic balloon pump 1:1, during the first 5 hours of weaning (frequency rate reduced to 1:2 in the RB group and volume decreased by 10%/h in the VB group), after 1 hour of frequency rate 1:3 in the RB group or a volume decrease by 75% in the VB group, 2 hours after withdrawal, and 4 hours after withdrawal. Results. The animals weaned by progressive VB deflation showed a greater degree of vasodilation, better cardiac output and stroke volume, fewer negative values of cardiac cycle efficiency, and higher dP/dT(max) compared with those weaned by RB reduction (p < 0.05 for all). The VB group also exhibited increased coronary flow, lower oxygen consumption of the myocardium, and coronary resistance during VB weaning (p < 0.05 for all). The serum lactate level was lower in the VB group at each experimental point (p < 0.05 for all), but visceral flows were scarcely affected by the weaning method. Conclusions. Volume reduction was the most effective weaning method considering that frequency reduction weaning was responsible for significant negative effects on hemodynamics and coronary circulation. (C) 2016 by The Society of Thoracic Surgeons

Aims To assess the results and impact of lesion set and surgical technique on long-term success of surgical ablation during mitral surgery. Methods and results The patient population consisted of 685 subjects with persistent and long-standing persistent atrial fibrillation (AF) undergoing cardiac surgery for mitral valve disease as the primary indication and concomitant ablation between January 2003 and January 2012 at three institutions. One hundred and sixty-six underwent unipolar (24.2%), 371 (54.2%) bipolar, and 148 (21.6%) had combined ablation. Median follow-up was 58.4 months (interquartile range 43.3–67.9). To appropriately account for death, a competing risk model was employed to identify predictors of cumulative incidence of recurrent AF among lesion set and surgical techniques. Eight-year freedom from recurrent arrhythmia without antiarrhythmic drugs was 0.60 ± 0.02. Success rate was higher using bipolar radiofrequency (RF) ( P < 0.001), after performing mitral isthmus line ( P = 0.003) and following the biatrial technique ( P < 0.001). Competing risk regression revealed that use of unipolar RF [sub-hazard ratio (SHR) 2.41 (1.52–3.43), P < 0.001], combined unipolar/bipolar ablation [SHR 1.93 (0.89–2.57), P = 0.003] and the absence of right atrial ablation [SHR 2.79 (1.27–3.48), P < 0.001] were predictors of cumulative incidence of long-term recurrence. Conclusions Our experience suggests that the use of bipolar clamp improves long-term results in surgical treatment of AF and that right-sided ablation should be routinely added. Randomized studies are necessary to confirm our findings.

Purpose Data on epicardial contact force efficacy in dual epicardial–endocardial atrial fibrillation ablation procedures are lacking. We present an in vitro study on the importance of epicardial and endocardial contact forces during this procedure. Methods The in vitro setup consists of two separate chambers, mimicking the endocardial and epicardial sides of the heart. A circuit, including a pump and a heat exchanger, circulates porcine blood through the endocardial chamber. A septum, with a cut out, allows the placement of a magnetically fixed tissue holder, securing porcine atrial tissue, in the middle of both chambers. Two trocars provide access to the epicardium and endocardium. Force transducers mounted on both catheter holders allow real-time contact force monitoring, while a railing system allows controlled contact force adjustment. We histologically assessed different combinations of epi-endocardial radiofrequency ablation contact forces using porcine atria, evaluating the ablation’s diameters, area, and volume. Results An epicardial ablation with forces of 100 or 300 g, followed by an endocardial ablation with a force of 20 g did not achieve transmurality. Increasing endocardial forces to 30 and 40 g combined with an epicardial force ranging from 100 to 300 and 500 g led to transmurality with significant increases in lesion’s diameters, area, and volumes. Conclusions Increased endocardial contact forces led to larger ablation lesions regardless of standard epicardial pressure forces. In order to gain transmurality in a model of a combined epicardial–endocardial procedure, a minimal endocardial force of 30 g combined with an epicardial force of 100 g is necessary.