Cardiac arrest and post-discharge mortality in patients with myocardial infarction: A large-scale nationwide registry analysis.

Background: Cardiac arrest is a serious complication of acute myocardial infarction. The implementation of contemporary approaches to acute myocardial infarction management, including urgent revascularization procedures, has led to significant improvements in short-term outcomes. However, the extent of post-discharge mortality in patients experiencing cardiac arrest during acute myocardial infarction remains uncertain. This study aimed to determine the post-discharge outcomes of patients with cardiac arrest. Methods: We analysed data from the J-PCI OUTCOME registry, a Japanese prospectively planed, observational, multicentre, national registry of percutaneous coronary intervention involving consecutive patients from 172 institutions who underwent percutaneous coronary intervention and were discharged. Patients who underwent percutaneous coronary intervention for acute myocardial infarction between January 2017 and December 2018 and survived for 30 days were included. Mortality in patients with and without cardiac arrest from 30 days to 1 year after percutaneous coronary intervention for acute myocardial infarction was compared. Results: Of the 26,909 patients who survived for 30 days after percutaneous coronary intervention for acute myocardial infarction, 1,567 (5.8%) had cardiac arrest at the onset of acute myocardial infarction. Patients with cardiac arrest were younger and more likely to be males than patients without cardiac arrest. The 1-year all-cause mortality was significantly higher in patients with cardiac arrest than in those without (11.9% vs. 2.8%, p < 0.001) for all age groups. Multivariable analysis showed that cardiac arrest was an independent predictor of all-cause long-term mortality (hazard ratio: 2.94; 95% confidence interval: 2.29-3.76). Conclusions: Patients with acute myocardial infarction and concomitant cardiac arrest have a worse prognosis for up to 1 year after percutaneous coronary intervention than patients without cardiac arrest.

Impact of vessel volume on thermodilution measurements in patients with coronary microvascular dysfunction.

BACKGROUND: Two invasive methods are available to estimate microvascular resistance: bolus and continuous thermodilution. Comparative studies have revealed a lack of concordance between measurements of microvascular resistance obtained through these techniques. AIMS: This study aimed to examine the influence of vessel volume on bolus thermodilution measurements. METHODS: We prospectively included patients with angina with non-obstructive coronary arteries (ANOCA) undergoing bolus and continuous thermodilution assessments. All patients underwent coronary CT angiography to extract vessel volume. Coronary microvascular dysfunction was defined as coronary flow reserve (CFR) < 2.0. Measurements of absolute microvascular resistance (in Woods units) and index of microvascular resistance (IMR) were compared before and after volumetric adjustment. RESULTS: Overall, 94 patients with ANOCA were included in this study. The mean age was 64.7 ± 10.8 years, 48% were female, and 19% had diabetes. The prevalence of CMD was 16% based on bolus thermodilution, while continuous thermodilution yielded a prevalence of 27% (Cohen's Kappa 0.44, 95% CI 0.23-0.65). There was no correlation in microvascular resistance between techniques (r = 0.17, 95% CI -0.04 to 0.36, p = 0.104). The adjustment of IMR by vessel volume significantly increased the agreement with absolute microvascular resistance derived from continuous thermodilution (r = 0.48, 95% CI 0.31-0.63, p < 0.001). CONCLUSIONS: In patients with ANOCA, invasive methods based on coronary thermodilution yielded conflicting results for the assessment of CMD. Adjusting IMR with vessel volume improved the agreement with continuous thermodilution for the assessment of microvascular resistance. These findings strongly suggest the importance of considering vessel volume when interpreting bolus thermodilution assessment.

Evaluation of the direction and extent of ice formation during cryoballoon ablation: an experimental study.

BACKGROUND: The distal hemisphere of a balloon is generally cooled during cryoapplication. However, a wide ablation area can be acquired after cryoballoon ablation. This study aimed to evaluate the extent of ice formation on two types of balloon surfaces through experimental and simulation studies. METHODS: A standard cryoballoon (SCB; Arctic Front Advance Pro, Medtronic) and novel cryoballoon (NCB; POLARx, Boston Scientific) were frozen for 240 s in 36 °C normal saline solution to observe ice formation on the balloon surface. Pieces of porcine tissue were placed between the upper and lower sides of the balloon, and the balloon was frozen in the horizontal direction for 240 s in 20 attempts (10 for SCB and NCB each). The measured areas of ice formation were evaluated and compared between the upper and lower sides of each balloon. RESULTS: Ice formation was greater on the lower side of the balloon than on the upper side. A larger area of ice formation in the tissue slab was observed on the lower side than on the upper side in both balloons, and the ice formation extended to the proximal hemisphere on the lower side of the balloon. The ice formation area in the NCB was significantly larger than that in SCB. CONCLUSIONS: Ice formation was significantly greater on the lower side of the cryoballoon than on the upper side and extended to the proximal hemisphere of the balloon, which might facilitate the acquisition of a wide ablation area on the left atrial posterior wall after cryoballoon ablation. Different ice formation after cryoballoon ablation Greater ice formation on the lower side of cryoballoon and an extensive ice formation in the proximal hemisphere, especially in novel cryoballoon.

Usefulness of the Snare Technique During Leadless Pacemaker Implantation for a Patient with a Severely Dilated Right Atrium.

We report here the case of a 92-year-old woman with atrial fibrillation bradycardia in which leadless pacemaker implantation was performed with a difficult delivery of the catheter sheath due to an extremely large right atrium. Using a snare technique with correction of the direction of the force on the catheter toward the right ventricle (RV) can result in successful delivery of the pacemaker catheter and stable placement of the pacemaker system in the RV septum. This specific snare technique has the potential to facilitate leadless pacemaker implantation safely in a severely dilated chamber of the heart, making this technique effective to use in clinical practice.

Difficulty removing a leadless pacemaker in a post-transfusion patient.

A 99-year-old woman with atrial fibrillation bradycardia and symptomatic long pauses underwent a leadless pacemaker implantation after red blood cell transfusion due to anaemia. The patient's blood tests after transfusion showed hypercoagulability; haematocrit, haemoglobin and fibrinogen levels were increased from 24.5% to 33.2%, 76 g/L to 111g/L, and 346 mg/dL to 646 mg/dL, respectively. Blood tests showed no hereditary hypercoagulability disorder and she had no history of thrombophilia. A leadless pacemaker was implanted in the correct position in the right ventricle. Heparin was administered after sheath insertion and the leadless pacemaker system was thoroughly flushed with heparinised saline before the tether was cut; however, removing the tether after leadless pacemaker implantation was difficult because clots had formed on the tether.

Prevalence and clinical outcomes of triglyceride deposit cardiomyovasculopathy among haemodialysis patients.

OBJECTIVE: To evaluate the effect of triglyceride deposit cardiomyovasculopathy (TGCV) on the cardiovascular outcomes in haemodialysis (HD) patients with suspected coronary artery disease (CAD). METHODS: This retrospective single-centre observational study included data from the cardiac catheter database of Narita Memorial Hospital between April 2011 and March 2017. Among 654 consecutive patients on HD, the data for 83 patients with suspected CAD who underwent both [123I]-ß-methyl-iodophenyl-pentadecanoic acid scintigraphy and coronary angiography were analysed. Patients were divided into three groups: definite TGCV (17 patients), probable TGCV (22 patients) and non-TGCV control group (44 patients). The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction and non-fatal stroke assessed for up to 5 years of follow-up. RESULTS: The prevalence of definite TGCV was approximately 20% and 2.6% among consecutive HD patients with suspected CAD and among all HD patients, respectively. At the end of the median follow-up period of 4.7 years, the primary endpoint was achieved in 52.9% of the definite TGCV patients (HR, 7.45; 95% CI: 2.28 to 24.3; p<0.001) and 27.3% of the probable TGCV patients (HR, 3.28; 95% CI: 0.93 to 11.6; p=0.066), compared with that in 9.1% of the non-TGCV control patients. Definite TGCV was significantly and independently associated with cardiovascular mortality and outcomes among HD patients in all multivariate models. CONCLUSIONS: TGCV is not uncommon in HD patients and is associated with an increased risk of cardiovascular events including cardiovascular death. Thus, TGCV might be a potential therapeutic target.

Clinical feasibility of resting full-cycle ratio as a unique non-hyperemic index of invasive functional lesion assessment.

The resting full-cycle ratio (RFR) is a new physiologic index to assess myocardial ischemia. RFR and fractional flow reserve (FFR), the conventionally used index, have not been directly compared in evaluating the entire cardiac cycle. Accordingly, we aimed to compare the diagnostic performance of RFR directly with FFR and clarify the clinical feasibility of RFR as a unique non-hyperemic index in evaluating the cardiac cycle. The diagnostic performance of RFR was compared with FFR using an automated online calculation software. A total of 156 consecutive patients with 220 intermediate lesions were enrolled. RFR showed significant correlation with FFR (r = 0.774, p < 0.001). RFR systole and RFR diastole did also with FFR (r = 0.918, p < 0.001, and r = 0.733, p < 0.001, respectively). With FFR < 0.80 as a reference standard, RFR showed good diagnostic accuracy (DA: 80.5%), similar DA between RFR systole and RFR diastole (79.6% and 87.5%, p = 0.58, respectively), and good DA in any lesion locations, especially in non-left anterior descending coronary artery (LAD) lesions (73.7% and 87.6% for LAD vs. non-LAD, p < 0.05, respectively). RFR is a feasible and reliable non-hyperemic index regardless of the difference in cardiac cycle in evaluating physiological lesion severity in daily practice.