Obstructive Sleep Apnea and Atrial Fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a chronic sleep disorder more common in older men. It has been shown that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is significantly underdiagnosed. This review, including 54,271 patients, carried out a meta-analysis to investigate the association between OSA and AF. We also performed a meta-regression to explore cofactors influencing this correlation. A strong link was found between these two disorders. The incidence of AF is 88% higher in patients with OSA. Age and hypertension independently strengthened this association, indicating that OSA treatment could help reduce AF recurrence. Further research is needed to confirm these findings. Atrial Fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a regulatory respiratory disorder of partial or complete collapse of the upper airways during sleep leading to recurrent pauses in breathing. OSA is more common in older men. Evidence exists that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is underdiagnosed. In order to investigate the incidence of AF in OSA patients, we carried out a meta-analysis including 20 scientific studies with a total of 54,271 subjects. AF was present in 4801 patients of whom 2203 (45.9%) had OSA and 2598 (54.1%) did not. Of a total of 21,074 patients with OSA, 2203 (10.5%) had AF and 18,871 (89.5%) did not. The incidence of AF was 88% higher in patients with OSA. We performed a meta-regression to explore interacting factors potentially influencing the occurrence of AF in OSA. Older age and hypertension independently strengthened this association. The clinical significance of our results is that patients with OSA should be referred early to the cardiologist. Further research is needed for the definition of the mechanisms of association between AF and OSA.

Breast Cancer and Atrial Fibrillation.

This study aims to establish the incidence of atrial fibrillation (AF) in breast cancer (BC) patients, focusing on staging and anti-cancer treatment. A meta-analysis was conducted to investigate the incidence of AF in BC patients and compare this incidence to other cancers. Furthermore, we evaluated the occurrence of AF as an adverse effect of biological therapies vs. non-biological therapies vs. biological therapies + non-biological therapies in BC. Finally, we compared the incidence of AF in early BC and metastatic BC. Thirty studies were included. Twenty-two studies focused on BC, encompassing 166,271 patients. In the BC group, 2.7% of patients developed AF, while in the "all cancer" group, 5.8% of patients developed AF. In addition, there was no difference between different types of therapies (p = 0.61) and between early and metastatic BC (p = 0.57). The type of anti-cancer therapy and the staging of BC does not influence AF's occurrence in this neoplastic disease.

Aortic flow below and visceral circulation during aortic counterpulsation: Evaluation of an in vitro model.

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.

In vivo preliminary test of a new biparietal bidirectional bipolar radiofrequency magnetic coupling system.

BACKGROUND: To test in vivo a new design prototype for radio frequency (RF) ablation. METHODS: A prototype based on a concept of endo-epicardial biparietal bipolar RF ablation with the atrial tissue interposed and consisting of two specular endocardial-epicardial catheters was tested in four pigs (80±5 kg). The endocardial catheter was introduced into the left atrium through the left atrial appendage on the beating heart. The epicardial counterpart was placed manually on the atrial epicardial surface. The coupling of the two catheters was achieved using a neodymium magnet around the gold plate electrode, and RF was applied to the interposed tissue. The hearts were excised, and the lesions were examined using morphometric evaluation. RESULTS: The RF application resulted in transmural lesions in all of the four animals tested. In these animals the maximum endocardial width (Wendo ) was 6.34 ± 0.25, 6.54 ± 0.33, 6.36 ± 0.57, and 6.49 ± 0.96 mm. The pericardial width (Wepi ) was similar: 6.37 ± 0.47, 6.58 ± 0.32, 6.35 ± 0.56 and 6.53 ± 0.94 mm. The lesion area was 924.78, 949.25, 944.25, and 926.05 mm2 , and the lesion volume was 92.47, 94.92, 94.42, and 92.60 mm3 , respectively. CONCLUSIONS: The idea of an endocardial-epicardial bidirectional biparietal bipolar radiofrequency tool such that the atrial tissue is fully interposed between the two RF poles might be promising for future clinical applications. Further research is warranted.

Surgical Risk Factors for Ischemic Stroke Following Coronary Artery Bypass Grafting. A Multi-Factor Multimodel Analysis.

Background: Ischemic stroke after coronary artery bypass (CABG) has been often linked to aortic manipulation during surgery. Objectives: The objective of the study was to estimate the rate of postoperative ischemic stroke within 30 days from CABG by surgical risk factors alone or in combination. Methods: The multinomial propensity score for multiple treatments was used to create six models with a total of 16,255 consecutive patients undergoing isolated CABG. For each model, a different classification variable was used to stratify patients. Results: Balance achieved in all models was substantial, enabling unbiased estimation of the treatment estimand. Both off-pump techniques with (0.009; 95% CI 0.006-0.011) or without proximal anastomoses (0.005; 0.005-0.003), and surgery performed on the beating heart using cardiopulmonary bypass with (0.009; 0.006-0.011) or without proximal anastomoses (0.024; 0.021-0.029) showed a mean stroke estimate significantly lower than the other techniques. Off-pump surgery and on-pump surgery without an aortic cross-clamp yielded nearly equal incidences of stroke (0.012; 0.008-0.015 and 0.018; 0.012-0.023, respectively). Using an aortic cross-clamp significantly increased the stroke estimate (0.075; 0.061-0.088), whereas using a side-biting clamp did not (0.039; 0.033-0.044). The number of aortic touches (0.029; 0.026-0.031) and the number of proximal anastomoses (0.044; 0.035-0.047) did not significantly increase the incidence of stroke. Conclusions: Aortic cross-clamping was found to be the primary cause of post-CABG ischemic stroke. Instead, additional aortic manipulation from a side-biting clamp, on-pump surgery, multiple aortic touches, number of proximal anastomoses, and aortic cannulation were found not to increase the estimate of stroke significantly. Further research on this topic is warranted.

Biparietal bidirectional bipolar radiofrequency in hybrid cardiac ablation: an in vitro evaluation.

OBJECTIVES: The 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]. METHODS: Fresh 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. RESULTS: Transmural 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 < 0.001). CONCLUSIONS: Although 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.

New Biparietal Bipolar Catheter Prototype for Hybrid Atrial Fibrillation Ablation.

OBJECTIVE: To 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. METHODS: A 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. RESULTS: Forty 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 (L MAX) was 7.297 mm (0.006), epicardial maximum length (L EPI) 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 mm2 and 101.85 ± 3.65 mm3, respectively. CONCLUSIONS: Our prototype showed very promising results. The next step will be to enhance the design for clinical application.

Comparison between biparietal bipolar and uniparietal bipolar radio frequency ablation techniques in a simultaneous procedural setting.

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 < 0.05): Moreover, maximum epicardial and endocardial diameters (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 < 0.05). We observed the same tendency in lesion depth: The total area and volume (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 < 0.05). 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.

Patient survival in severe low-flow, low-gradient aortic stenosis after aortic valve replacement or conservative management.

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.

Quantification of Death Risk in Relation to Sex, Pre-Existing Cardiovascular Diseases and Risk Factors in COVID-19 Patients: Let's Take Stock and See Where We Are.

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.

One-Stage Versus Sequential Hybrid Radiofrequency Ablation: An In Vitro Evaluation.

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.

Is Peripheral Artery Disease an Independent Predictor of Isolated Coronary Artery Bypass Outcome?

AIM: 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. METHOD: 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. RESULTS: 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 (p<0.001) 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 p<0.001), and postoperative low cardiac output (p=0.01). CONCLUSIONS: 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.

Are recurrence of ischemic mitral regurgitation and left ventricular reverse remodeling after restrictive annuloplasty ring dependent?

OBJECTIVE: This meta-analysis investigates MR recurrence and degree of left ventricular reverse remodeling (LVRR) in CIMR patients in mitral annuloplasty employing different ring designs. BACKGROUND: The deeper understanding of complex changes caused by chronic ischemic mitral regurgitation (CIMR) have led to new generations of rings that, by maintaining normal 3D annular geometry are supposed to enhance long-term repair durability. METHODS: A meta-analysis of all available reports in literature of MV repair through different ring design was conducted. Meta-regression was performed to investigate the impact of mitral ring characteristics related to flexibility, planarity, symmetry and single type utilized. Twenty studies encompassing a total of 1876 patients were included at the end of the selection process. RESULTS: At meta-regression recurrence of MR was not influenced by the ring employed. Nonetheless, the event rate of MR recurrence in planar rings was 19%. Vs. 11% observed with non-planar rings. Recurrence rate in patients implanted with symmetric rings was 14% whereas it was 7% in asymmetric rings. The non-planar asymmetric IMR-ETlogix showed the lowest recurrence rate (6%). Furthermore, in planar group the reduction of pre- and post-operative LVEDD was - 4%. In the non-planar group, the LVEDD was reduced by 8.6%. In patients implanted with symmetric rings LVEDD reduction was 10.8%. LVRR in the asymmetric group was -5.8%. CONCLUSION: MR recurrence occurred the least with asymmetric rings with less disproportionate asymmetry. In contrast, LVRR occurred at a greater extent in symmetric rings.

Papillary muscle intervention vs mitral ring annuloplasty in ischemic mitral regurgitation.

BACKGROUND AND AIMS: 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. METHODS: 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. RESULTS: 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). 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 <10%. No difference was detected between PM relocation/repositioning and papillary muscle approximation in terms of LVRR (p = .33). CONCLUSIONS: 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.

Superior mesenteric flow pattern during counterpulsation: is simply a shorter balloon the solution for visceral hypoperfusion?

OBJECTIVES: We studied the flow pattern in the superior mesenteric artery (SMA) during intra-aortic balloon pump support, comparing 2 intra-aortic balloons of 2 different lengths. METHODS: Sixteen Landrace pigs (mean weight 84.0 kg ± 6.0) were used in this study. The animals were randomly assigned to 2 groups: group 1 received an 8-Fr, 40-ml standard balloon; group 2 received an 8-Fr, 40-ml short balloon. SMA flow was measured during early, mid- and telediastole. RESULTS: The standard balloon led to a reduction in SMA flow in early diastole (P < 0.001), a negative flow in mid-diastole (P < 0.001) and a reincrease in telediastole (P < 0.001). In contrast, in early diastole a significant reduction was observed with the short balloon (P < 0.001), followed by another drop in mid-diastole (P < 0.001), without reaching negative values and by a telediastolic increase (P < 0.001). SMA flows were comparable between balloons during early diastole (P = 0.66), whereas they were higher with the short balloon during mid (P < 0.001) and telediastole (P = 0.02). Overall, the diastolic area was significantly larger when the short balloon was used (P < 0.001). Finally, during counterpulsation, mesenteric resistances increased significantly (P < 0.001), although, with the short balloon, they were lower than with the standard balloon (P = 0.01). CONCLUSIONS: Despite better overall mean mesenteric diastolic flow, the short balloon leads to early- and mid-diastolic flow reduction, although to a lesser extent than the standard intra-aortic balloon pump balloon. Our data are a call for improvement in the design of the short balloon.

In situ skeletonized bilateral thoracic artery for left coronary circulation: a 20-year experience.

OBJECTIVES: Our goal was to analyse the outcomes in a patient population using a standardized technique for coronary artery bypass grafting (CABG) consisting of total arterial myocardial revascularization utilizing the in situ skeletonized bilateral thoracic artery for left coronary circulation. We also explored potential predictors of long-time unfavourable outcomes. METHODS: Patients undergoing total arterial myocardial revascularization using in situ skeletonized bilateral thoracic artery for left coronary circulation between January 1997 and May 2017 were included prospectively in this study. The median follow-up (100% complete) was 103 months (interquartile range 61-189 months) and ranged from 1 to 245 months. RESULTS: A total of 1325 consecutive patients were recruited. During the follow-up period, there were 131 deaths (9.8%), 146 repeat revascularizations (11.0%) and 229 major adverse cardiac events (17.2%). The 18-year freedom from major adverse cardiac events was 62.6 ± 9.3%, 62.5 ± 6.3% and 53.9 ± 11.0%, respectively. Multivariable models showed that a left ventricular ejection fraction ≤35%, chronic obstructive pulmonary disease, peripheral vascular disease (P < 0.001), chronic kidney disease and age ≥80 years (P = 0.002) were independent predictors of diminished long-term survival. Moreover, peripheral vascular disease and off-pump coronary artery bypass (both, P < 0.001) predicted repeat revascularization. Finally, age ≥80 years, peripheral vascular disease, left ventricular ejection fraction ≤35%, off-pump coronary artery bypass and chronic pulmonary obstructive disease were independent predictors of major adverse cardiac events during the long-term follow-up period (all, P < 0.001). CONCLUSIONS: Coronary artery bypass using the in situ skeletonized bilateral thoracic artery for left coronary circulation configuration for total arterial myocardial revascularization resulted in satisfactory long-term results with a low incidence of death and late events and may represent a technique of choice in selected patients having CABG. Larger and long-term prospective studies are, however, warranted.

Early outcomes following isolated coronary artery bypass surgery: Influence of peripheral artery disease.

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 < .001) than patients without PAD. CONCLUSIONS: The presence of peripheral arterial disease increases the incidence of postoperative stroke, AKD and limb ischemia requiring intervention, independent of patient characteristics, concomitant risk factors, surgical approaches, and techniques. Further larger studies are necessary to confirm our findings.

Clinical outcomes of automated anastomotic devices: A metanalysis.

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 < .001; I2 = 72.907%, P = .002; Egger's test: intercept = -2.47, P = 0.16; Begg and Mazumdar test: τ = -0.20, p = 0.57). Graft patency was 90.5% (80.4 to 95.7, P < .001; I2 = 76.823%, P = .005; Egger's test: intercept = -3.04, P = .10; Begg and Mazumdar test: τ = -0.67, P = .17). Furthermore, the overall incidence of MACEs was 3.7% (1.3-10.4, P < .001; I2 = 51.556%, P = .103; Egger's test: intercept = -1.98, P = < .11; Begg and Mazumdar test: τ = -0.67, P = .17). Finally, mortality within 1 year was 5% (3.5-7, P < .001; I2 = 29.675%, P = .202; Egger's test: intercept = -0.91, P = .62; Begg and Mazumdar test: τ = -0.04, P = .88). CONCLUSIONS: APADs do not seem to be correlated with a reduction of either neurological events or mortality. By contrast, these tools showed satisfactory one-year graft patency and a low incidence of MACEs. Further research on this topic is warranted.

Continuous monitoring of membrane lung carbon dioxide removal during ECMO: experimental testing of a new volumetric capnometer.

BACKGROUND: Extracorporeal membrane oxygenation constitutes a complex support modality, and accurate monitoring is required. An ideal monitoring system should promptly detect ECMO malfunctions and provide real-time information to optimize the patient-machine interactions. We tested a new volumetric capnometer which enables continuous monitoring of membrane lung carbon dioxide removal (V'CO2ML), to help in estimating the oxygenator performance, in terms of CO2 removal and oxygenator dead space (VDsML). METHODS: This study was conducted on nine pigs undergoing veno-arterial ECMO due to cardiogenic shock after induced acute myocardial infarction. The accuracy and reliability of the prototype of the volumetric capnometer (CO2RESET™, by Eurosets srl, Medolla, Italy) device was evaluated for V'CO2ML and VDsML measurements by comparing the obtained measurements from the new device to a control capnometer with the sweep gas values. Measurements were taken at five different levels of gas flow/blood flow ratio (0.5-1.5). Agreement between the corresponding measurements was taken with the two methods. We expected that 95% of differences were between d - 1.96s and d + 1.96s. RESULTS: In all, 120 coupled measurements from each device were obtained for the V'CO2ML calculation and 40 for the VDsML. The new capnometer mean percentage bias (95% confidence interval limits of agreement) was 3.86% (12.07-4.35%) for V'CO2ML and 2.62% (8.96-14.20%) for VDsML. A negative proportional bias for V'CO2ML estimation with the new device was observed with a mean of 3.86% (12.07-4.35%). No correlations were found between differences in the coupled V'CO2ML and VDsML measurements and the gas flow/blood flow ratio or temperature. Coupled measurements for V'CO2ML showed strong correlation (rs = 0.991; p = 0.0005), as did VDsML calculations (rs = 0.973; p = 0.0005). CONCLUSION: The volumetric capnometer is reliable for continuous monitoring of CO2 removal by membrane lung and VDsML calculations. Further studies are necessary to confirm these data.

Superior mesenteric and renal flow patterns during intra-aortic counterpulsation.

NEW FINDINGS: 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. ABSTRACT: 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.