National Cerebral and Cardiovascular Center

We hypothesized that deep learning-based post hoc denoising could improve the quality of cardiac CT for the 3D volume-rendered (VR) imaging of mitral valve (MV) prolapse. We aimed to evaluate the quality of denoised 3D VR images for visualizing MV prolapse and assess their diagnostic performance and efficiency. We retrospectively reviewed the cardiac CTs of consecutive patients who underwent MV repair in 2023. The original images were iteratively reconstructed and denoised with a residual dense network. 3DVR images of the “surgeon’s view” were created with blood chamber transparency to display the MV leaflets. We compared the 3DVR image quality between the original and denoised images with a 100-point scoring system. Diagnostic confidence for prolapse was evaluated across eight MV segments: A1-3, P1-3, and the anterior and posterior commissures. Surgical findings were used as the reference to assess diagnostic ability with the area under curve (AUC). The interpretation time for the denoised 3DVR images was compared with that for multiplanar reformat images. For fifty patients (median age 64 years, 30 males), denoising the 3DVR images significantly improved their image quality scores from 50 to 76 (P <.001). The AUC in identifying MV prolapse improved from 0.91 (95% CI 0.87–0.95) to 0.94 (95% CI 0.91–0.98) (P =.009). The denoised 3DVR images were interpreted five-times faster than the multiplanar reformat images (P <.001). Deep learning-based denoising enhanced the quality of 3DVR imaging of the MV, improving the performance and efficiency in detecting MV prolapse on cardiac CT. Graphical Abstract Deep learning-based post hoc denoising improved 3D cardiac CT imaging of the mitral valve, enhancing performance and efficiency in detecting prolapse

This clinical consensus statement revisits the role of left ventricular ejection fraction (LVEF) as a measurement of cardiac function, a prognostic marker and a major criterion to classify patients with heart failure, and gives new advice for clinical practice. Heart failure is traditionally classified on the basis of LVEF thresholds and this has major implications for treatment recommendations. However, the reproducibility of LVEF measurement is poor and its prognostic and diagnostic value lessens when it is above 45%, with no relationship with the severity of either cardiac dysfunction or outcomes at higher values. These limitations dictate the need for a more comprehensive approach to classify and assess heart failure focusing more on the trajectory of LVEF rather than to its absolute value. Furthermore, the assessment of LVEF is not required for the initiation of treatments like sodium–glucose cotransporter 2 inhibitors, mineralocorticoid receptor antagonists and diuretics in patients with suspected de novo heart failure and elevated N‐terminal pro‐B‐type natriuretic peptide levels. Future research utilizing advanced imaging techniques and biomarkers which can better characterize myocardial structure, metabolism and performance may facilitate the identification of alternative therapeutic targets and better ways to monitor heart failure therapies across the entire spectrum of LVEF.

Background: Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) values after initiating sacubitril/valsartan (Sac/Val) are considered a favorable prognostic factor in patients with heart failure (HF). However the relationship between the trajectory of repeated NT-proBNP measurements and cardiovascular events after Sac/Val remains uncertain. Methods and Results: A Japanese nationwide multicenter study enrolled 995 patients who were prescribed Sac/Val from August 2020 to August 2021. Of them, 434 patients who had a complete set of NT-proBNP measurements were divided into 3 groups: sustained-responder group (n=129), with ≥10% reduction in NT-proBNP at 1 month and further ≥10% reduction at 3 months; transient-responder group (n=161), with ≥10% reduction at 1 month but not at 3 months; and non-responder group (n=144), without ≥10% reduction at 1 month. There were no significant differences in the mean Sac/Val dose at each measurement point among the 3 groups. During a median follow-up of 456 (interquartile range: 371–549) days, the primary endpoint, which was either cardiovascular death or hospitalization for HF, occurred in 78 patients. Kaplan-Meier analysis revealed that the sustained-responder group had a significantly higher event-free survival rate among the 3 groups (Log-rank P<0.001). Conclusions: Repeated NT-proBNP monitoring and the pattern of the NT-proBNP trajectory after Sac/Val may be helpful in optimizing HF therapy and understanding the prognosis of HF.

Introduction Acetic acid in dialysis fluid has been reported to induce symptomatic hypotension and post‐dialysis fatigue. However, it remains unclear whether acetate‐free dialysate improves these outcomes due to the lack of comprehensive evidence. This systematic review and meta‐analysis aimed to compare the effects of acetate‐free dialysate with standard acetate‐containing dialysate using randomized controlled trials. Method We searched databases including MEDLINE, EMBASE, CENTRAL, and trial registries. Primary outcomes were fatigue, intradialytic hypotension (IDH), and all‐cause mortality. Secondary outcomes included dropout rate due to adverse events, serum bicarbonate levels, and acid–base balance (pH) at the study's end. The Cochrane risk of bias tool 2 for crossover trials assessed the risk of bias, and we used a random effects model for meta‐analyses, along with the GRADE approach to rate evidence certainty. Results We identified four randomized crossover trials involving 114 patients, all at high risk of bias due to period and carryover effects. The studies showed no significant impact on fatigue. Acetate‐free dialysate may slightly reduce IDH (OR 0.83, 95% CI 0.66 to 1.04; I2 = 79%, across two studies with 5872 sessions) with low certainty of evidence. Results for secondary outcomes, including bicarbonate levels and pH, were inconclusive due to very low certainty of evidence. Conclusion In conclusion, no clear benefit was observed for acetate‐free dialysate compared with dialysate containing low concentrations of acetate. Further studies are needed to definitively ascertain the benefits of low‐acetate dialysates in hemodialysis treatment.

Background Whether intravenous thrombolysis (IVT) should be administered prior to endovascular therapy (EVT) in patients with atherothrombotic stroke-related large vessel occlusion (AT-LVO) remains unclear. This study aimed to assess the efficacy and safety of IVT administered before EVT in this patient population. Methods We analysed the data from a multicentre registry of patients who underwent EVT for AT-LVO. Patients were categorised based on presumed mechanism of occlusion: in situ occlusion (intracranial group) or embolism from cervical artery occlusion/stenosis (tandem group). We compared the efficacy and safety of IVT before EVT in patients who received IVT (IVT stratum) and those who did not (non-IVT stratum). The primary outcome was a modified Rankin Scale score of 0–2 at 90 days. Results Among the 336 patients in the intracranial group, 99 patients underwent IVT. The rate of favourable functional outcomes did not differ between IVT and non-IVT strata (51.1% vs 47.6%; adjusted ORs (aORs) (95% CI), 1.18 (0.66 to 2.09)); whereas any intracranial haemorrhage (ICH) (10.1% vs 3.8%; aOR, 2.98 (1.01 to 9.26)) and mortality at 90 days (6.4% vs 1.3%; aOR, 4.66 (1.02 to 26.73)) were significantly higher in the IVT stratum. Among the 233 patients in the tandem group, 88 patients underwent IVT, with no significant differences in efficacy or safety outcomes between the strata. Conclusion In patients with AT-LVO, IVT before EVT did not improve outcomes and was associated with increased risk of ICH and mortality in those with in situ intracranial occlusion. IVT before EVT may not be recommended in patients with atherosclerotic intracranial occlusions.

Aims Plasma volume status (PVS) is recognized as a marker of systemic congestion, but its clinical utility in patients with mitral regurgitation (MR) undergoing transcatheter edge‐to‐edge mitral valve repair (M‐TEER) has not been well established. This study aimed to evaluate the prognostic significance of PVS in these patients. Methods and results Data from 3763 patients who underwent M‐TEER were analysed from a Japanese multicentre registry. Patients were classified into functional MR (FMR) and degenerative MR (DMR) according to MR aetiology, and the median PVS values for each were calculated (FMR 12.7, DMR 14.4). The median value was used as the cut‐off, stratifying the cohort into a high PVS group (n = 1882) and a low PVS group (n = 1881). All‐cause mortality, cardiovascular death, and heart failure (HF) hospitalization between these two groups were compared up to 3 years in the overall, FMR, and DMR populations. The cumulative incidence rates of all‐cause mortality, cardiovascular death, and HF hospitalization were higher in the high PVS group than in the low PVS group (47.0% vs. 22.2%, P < 0.001, 31.6% vs. 13.6%, P < 0.001, and 35.9% vs. 24.7%, P < 0.001, respectively). Similar trends in terms of all‐cause mortality, cardiovascular death, and HF hospitalization were observed in the FMR and DMR cohorts (all P < 0.05). In the multivariate Cox regression analysis, the high PVS compared with the low PVS group was independently associated with the increased risk of all‐cause death (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.01–1.03; P < 0.001), cardiovascular death (HR, 1.02; 95% CI, 1.01–1.03, P < 0.001) and HF hospitalization (HR, 1.02; 95% CI, 1.01–1.02, P < 0.001). An independent association between a high PVS and all‐cause death, cardiovascular death, and HF hospitalization was also found in FMR and DMR sub‐groups (all P < 0.05) while reducing MR severity to moderate or less after M‐TEER was associated with improved outcomes in both the high and low PVS groups. Conclusions Preoperative PVS is a strong independent prognostic marker in patients undergoing M‐TEER, correlating with increased risk of mortality and HF hospitalization. PVS may provide valuable clinical insights for patient stratification and management strategies in M‐TEER patients.

Although aortic valvular disease has various etiologies, recently, calcific aortic valve stenosis has been increasing. We analyzed the trends in the pathological characteristics of aortic valvular disease in the past four decades in Japan. The pathology department data for aortic valvular disease operated in our hospital documented 4508 patients from 1978 to 2022. Subsequently, trend analyses were performed over four periods: Period 1, 1978–1989 (618 cases); Period 2, 1990–1999 (903 cases); Period 3, 2000–2010 (1179 cases); and Period 4, 2011–2022 (1808 cases). We reviewed the pathological characterization of the resected aortic valves and categorized them based on the representative etiology of aortic valvular disease as congenital bicuspid, chronic rheumatic change, infective endocarditis, degenerative calcific change, and myxoid change. Our pathologic analysis revealed a significant decrease in the proportion of chronic rheumatic disease from 47% to 14%, an increase in the congenital bicuspid valve from 8% to 24%, and a rise of the degenerative calcific change of the aortic valve from 4% to 27% ( p < 0.001), especially significant increases in aortic stenosis. Calcification of the aortic valve may result from an active process similar to atherosclerosis, leading to aortic stenosis with increasing dyslipidemia in Japanese patients in 40 years.

Congenital vascular malformations, affecting 0.5% of the population, often occur in the head and neck, complicating treatment due to the critical functions in these regions. Our previous research identified distinct developmental origins for blood and lymphatic vessels in these areas, tracing them to the cardiopharyngeal mesoderm (CPM), which contributes to the development of the head, neck, and cardiovascular system in both mouse and human embryos. In this study, we investigated the pathogenesis of these malformations by expressing Pik3ca H1047R in the CPM. Mice expressing Pik3ca H1047R in the CPM developed vascular abnormalities restricted to the head and neck. Single-cell RNA sequencing revealed that Pik3ca H1047R upregulates Vegf-a expression in endothelial cells through HIF-mediated hypoxia signaling. Human samples supported these findings, showing elevated HIF-1α and VEGF-A in malformed vessels. Notably, inhibition of HIF-1α and VEGF-A in the mouse model significantly reduced abnormal vasculature. These results highlight the role of embryonic origins and hypoxia-driven mechanisms in vascular malformations, providing a foundation for the development of therapies targeting these difficult-to-treat conditions.

Introduction The role of corticosteroids in the management of ventricular tachyarrhythmia (VA) in cardiac sarcoidosis (CS) remains controversial. This study assessed the effect of early steroid initiation on VA recurrence rates in patients with CS and evaluated VA frequency before and after steroid therapy. Methods From a registry of 137 patients with CS with arrhythmias, those with VA and more than 60 days of follow‐up were included. Patients were categorized into three groups: previous‐on‐steroid, those using corticosteroids at the time of the first VA ( n = 15); early‐steroid, those with steroid initiation within 60 days ( n = 21); and no‐or‐delayed‐steroid, those without steroid use at 60 days from the first VA ( n = 35). The VA recurrence and timing were analyzed. Results The median age at the first VA was 60 years. Over a median follow‐up period of 81 (range: 4–345) months, 43 patients experienced VA recurrence. The median time to recurrence was 101, 33, and 17 months in the early‐steroid, no‐or‐delayed steroid, and previous‐on‐steroid groups, respectively. Corticosteroid use at 60 days was an independent predictor of VA recurrence at 120 months (hazard ratio: 2.257; p = 0.045 in the no‐or‐delayed steroid group and hazard ratio: 3.155; p = 0.021 in the previous‐on‐steroid group vs. the early‐steroid group). Low left ventricular ejection fraction (LVEF) was associated with frequent VA episodes. Corticosteroid initiation did not increase early VA episodes. Conclusion Early corticosteroid initiation after VA onset reduced the long‐term recurrence without increasing early episodes. Cases of repetitive VA were common in those with low LVEF.

Aims The clinical guidelines categorize heart failure (HF) based on left ventricular ejection fraction (LVEF). However, the current LVEF cutoffs, 40% and 50%, may not fully address the underlying characteristics and cardiovascular risk of HF, particularly for HF with higher LVEF. This study aimed to characterize HF with supranormal ejection fraction (HFsnEF) using different LVEF cutoffs (35%, 55%, and 70% for men, and 40%, 60%, and 75% for women). Methods and results This study divided 442 patients from the CHART‐Omics study into four groups: HF with reduced ejection fraction (HFrEF) ( n = 55, 65.5 years), HF with mildly reduced ejection fraction (HFmrEF) ( n = 125, 69.3 years), HF with normal ejection fraction (HFnEF) ( n = 215, 69.0 years) and HFsnEF ( n = 47, 67.1 years). When clinical backgrounds were adjusted and HFnEF served as the reference, HFsnEF carried an increased hazard ratio (HR) for the composite of cardiovascular death and HF hospitalization of 2.71 (95% confidence interval [CI] 1.10–6.66, p = 0.030), while HFrEF had a HR of 3.14 (95% CI 1.36–7.23, p = 0.007). HFsnEF was characterized by an increase in relative left ventricular wall thickness and a decrease in left ventricular dimensions, whereas increased left ventricular mass and dimensions characterized HFrEF. Quantitative analysis of 4670 plasma proteins showed essential differences between HFsnEF and HFrEF, for example, ‘protein synthesis’ versus ‘cell morphology’, ‘cellular assembly and organization’ and ‘nucleic acid metabolism’ for underlying pathophysiology, and ‘energy production’ versus ‘connective tissue disorders’ and ‘cell‐to‐cell signalling and interaction’ for prognostication. Conclusions Heart failure with supranormal ejection fraction, an unnoticed but emerging entity in HF, carries a similarly increased cardiovascular risk as HFrEF but has unique structural and plasma proteomic characteristics.

Background The assessment of left ventricular (LV) diastolic function based on the American Society of Echocardiography and the European Association of Cardiovascular Imaging (ASE/EACVI) guidelines requires measurement of several echocardiographic indices. However, these assessments often yield inconclusive results owing to the absence of measurable parameters. Multiple B-lines on lung ultrasound have been proposed as a method for evaluating pulmonary congestion. We aimed to evaluate the association between B-lines and LV diastolic function and to examine whether B-lines show potential as an alternative to conventional indices for assessing LV diastolic function. Methods This prospective study included 172 patients with pre-heart failure (HF) or HF. We investigated (i) the relationship between B-lines and LV diastolic function using echocardiography, (ii) the diagnostic accuracy of B-lines compared to echocardiography indices for estimating LV filling pressures and (iii) the relationship between B-lines and risk of hospitalisation for HF. Results Among patients for whom the ASE/EACVI guideline algorithm for LV diastolic dysfunction was available (n = 89), the number of B-lines typically increased with the severity of diastolic dysfunction grade. In patients who underwent left heart catheterisation (n = 20), the LV filling pressure was significantly correlated with B-lines (r = 0.690, P < 0.001). The diagnostic accuracy of B-lines for detecting high LV filling pressure was comparable to that of tricuspid regurgitation peak gradient (TRPG). When TRPG was replaced with B-lines to diagnose grade II or III diastolic dysfunction using the ASE/ESCVI algorithm, sensitivity remained comparable (0.80); however, specificity improved (0.80 vs. 0.50). In patients who underwent lung ultrasound while they were hemodynamically stable and were followed up for prognosis (median, 730 days; n = 75), 14 hospitalisations for HF were observed. Kaplan–Meier analysis revealed that the high B-line group had a significantly higher incidence of hospitalisation events for HF (P = 0.036, log-rank test). Conclusion B-lines have shown potential as an alternative to conventional indices for assessing LV diastolic dysfunction. Graphical Abstract

Destination therapy (DT) using an implantable left ventricular assist device (i-LVAD) in Japan has expanded treatment options for patients with out-of-hospital cardiac arrest (OHCA) receiving extracorporeal cardiopulmonary resuscitation (ECPR). However, achieving hemodynamic stabilization and improved peripheral organ perfusion is essential. In patients with OHCA, percutaneous mechanical circulatory support (MCS) devices may be inadequate in some cases, necessitating surgical MCS. Despite the growing importance of MCS upgrading, awareness among Japanese emergency physicians remains unclear. We aimed to assess awareness of advanced MCS upgrading strategies in refractory patients after ECPR. A nationwide survey of 293 emergency and critical care centers in Japan assessed awareness of i-LVAD therapy after ECPR. The questionnaire collected data on demographics, LVAD strategy recognition, MCS upgrade practices, and barriers. Of 90 facilities (31%) that responded, 87 (30%) consented to using their responses in the analysis. Awareness of DT was 59.8%. Notably, 66.7% and 70.1% of the respondents recognized that MCS upgrading could lead to i-LVAD treatment and heart transplantation, respectively. The major barrier to MCS upgrade therapy was the facility’s inability to implement it. DT awareness was similar between IMPELLA-registered and non-registered facilities, but i-LVAD indication recognition was higher in IMPELLA-registered facilities (78.0% vs. 51.4%, P = 0.009). The low survey response rate suggests limited MCS upgrade awareness among Japanese emergency physicians. Although facilities recognize pathways to i-LVAD and transplantation, barriers to their implementation persist. IMPELLA-registered facilities showed higher i-LVAD indication recognition, reflecting their accessibility to LV unloading devices and connections with backup hospitals.

Purpose Endovascular treatment (EVT) for acute ischemic stroke (AIS) with mild symptoms (National Institute of Health Stroke Scale [NIHSS] score of ≤ 5) has a specific concern about early neurological deterioration (END) after the procedure, but its significance remains unclear. This study aims to examine the prognostic impact and characteristics of END in this patient population. Methods We conducted a post-hoc analysis of the Japan Registry of NeuroEndovascular Therapy 4, enrolling 13,479 patients who underwent EVT for AIS at 166 participating centers between 2015 and 2019. We included patients with AIS and NIHSS scores ≤ 5 and compared outcomes (modified Rankin Scale [mRS] score at 30 days) between patients with and without END after EVT. Multivariate logistic regression models were used to explore associations between END and outcomes and risk factors for END. Results Of 503 patients analyzed, 66 (13%) developed END. Patients who developed END had a lower proportion of mRS scores of 0–2 at 30 days than the No-END group (17% vs. 80%, P < 0.0001), with an adjusted odds ratio (OR) of 0.04 (95% confidence interval [CI], 0.02–0.11). Mortality within 30 days was higher among patients with END (9.1% vs. 0.7%, P < 0.0001). A multivariable logistic regression model identified that factors associated with END included age ≥ 75 years (adjusted OR 3.67; 95% CI, 1.78–7.55), ASPECTS (adjusted OR 0.82; 95% CI, 0.69–0.97), NIHSS scores before EVT of 0–2 compared with those of 3–5 (adjusted OR 2.11; 95% CI, 1.04–4.25), and unsuccessful recanalization (adjusted OR 8.39; 95% CI, 3.90–18.0). Conclusion END after EVT for AIS with mild symptoms was relatively common and associated with worse outcomes. Risk stratification for END and successful recanalization would be crucial, particularly for EVT candidates with mild symptoms.

Background In Japan, type 2 diabetes mellitus (T2DM) is a major health concern due to its increasing prevalence and associated complications, including diabetic nephropathy and dialysis. Although the positive relationship between annual health checkups and health outcomes is well-documented, the impact of skipping health checkups on T2DM and its progression to dialysis remains unclear. This study aimed to explore the association between the frequency of annual health checkups and DM-related indices and the potential impact of early intervention in preventing dialysis. Methods The study included citizens aged ≥ 40 years from Nobeoka City, Japan (n = 22,094). Health checkup data from 2021 were analyzed, and participants were categorized into four groups based on their health checkup attendance between 2018 and 2020. Logistic regression analyses evaluated the association between health checkup frequency and DM-related indices, such as hemoglobin A1c and estimated glomerular filtration rate. These indices are used to diagnose DM and evaluate its severity. The time to dialysis for citizens without health checkups was estimated under untreated and treated scenarios using a previously published model. Results Among the 3,472 participants who underwent health checkups in 2021, 2,098 (60.4%) were women, and 1,374 (39.6%) were men. Citizens who missed health checkups for 3 consecutive years had a higher risk of T2DM than those who had annual checkups (odds ratio = 4.69, 95% confidence interval: 2.78–7.94). No significant difference was observed in T2DM rates between those who attended once or twice and those who attended annually. Simulations for high-risk citizens showed that 32 of 39 individuals may require dialysis during their lifetime; however, early intervention could prevent dialysis in 31 of them. Conclusions Citizens who skipped health checkups for 3 consecutive years or longer had a higher risk of T2DM, highlighting the need for targeted public interventions to prevent DM in this population.

Background: Chronic obstructive pulmonary disease (COPD) is one of the most common comorbidities in patients with chronic heart failure (CHF). A growing number of patients are suffering from both COPD and CHF, and these conditions worsen each other. Inhaled bronchodilator therapy with long-acting muscarinic antagonist (LAMA) and long-acting β2-agonist (LABA) in combination is currently the mainstay of treatment for COPD. However, the effect of LAMA/LABA on HF with COPD remains unknown. Methods and Results: The COPD-HF trial is a multicenter, double-arm, open-label, exploratory, investigator-initiated clinical study to investigate the effect of LAMA/LABA on HF in patients suffering from both COPD and CHF. The participants are randomly assigned (1 : 1) to the LAMA/LABA (tiotropium+olodaterol FDC (fixed-dose combination) 5/5 ug) group (once a day, 2 inhalations) or non-pharmacological treatments for COPD as a control group. The planned number of patients to be enrolled in this trial is 54 in total (27 in each group). The participants are followed up for 12 weeks with and without LAMA/LABA. The primary endpoint is the change in plasma B-type natriuretic peptide levels from the baseline to the end of this study (12 weeks). Conclusions: The COPD-HF trial will investigate the efficacy of LAMA/LABA on HF in patients with COPD and CHF.

Background: Although tricuspid regurgitation (TR) is no longer considered a negligible disease, its detailed status in real-world heart failure (HF) patients remains unknown. Methods and Results: From the KUNIUMI registry, we evaluated data for 1,646 consecutive HF patients. The primary endpoint was all-cause mortality over a median follow-up period of 3.0 years (interquartile range 1.4–3.0 years). Of the 1,646 HF patients, 369 (22.4%) had moderate or greater TR; the mean (±SD) age of these patients was 82.0±8.5 years. Atrial functional TR was the most common etiology of TR in HF patients with moderate or greater TR (70.7%), and was more common in HF patients with severe than moderate TR (75.5% vs. 65.3%; P=0.032). The mortality rate was high in HF patients with severe and moderate TR (27.1% and 17.0%, respectively). During follow-up, 33.1% of HF patients with moderate TR progressed to severe TR, and showed unfavorable all-cause mortality compared with those with unchanged TR. Atrial functional TR was a more common etiology in HF patients with moderate TR and worsened TR than in those with unchanged TR (84.6% vs. 59.5%; P=0.004). Right atrial enlargement was independently correlated with worsened TR. Conclusions: Moderate or greater TR was prevalent in 22.4% of the real-world super-aged HF population. Even HF patients with moderate TR had poor outcomes, with right atrial remodeling a key factor for worsened TR.

Endotracheal intubation plays a crucial role in airway management in mice. Transoral endotracheal intubation (TEI) offers a less invasive alternative to tracheostomy and is more ideal for chronic experiments. Despite the development of various TEI techniques in mice, the lack of accessible and well-established methods that do not require specialized equipment hinders routine research. We developed a feasible and highly successful method for TEI in C57BL/6JJcl mice using a combination of commercially available research equipment. A success rate of 97.5% was achieved within 21.2 ± 8.9 sec (mean [standard deviation]) with no observed complications in the 40 mice studied. This method simplifies TEI without specialized tools and provides practical guidance for consistent application in routine research settings.

Background Ventricular parasystole is strongly associated with ventricular fibrillation (VF) in patients with non-ischaemic cardiomyopathy. However, the relationship between ventricular parasystole and cardiac sarcoidosis (CS) remains unclear. The purpose of this study was to examine the prevalence of parasystole in patients with CS. Methods This was a retrospective observational study of 214 consecutive patients diagnosed with CS (mean age: 69±12 years, 104 males, median follow-up period: 6.8 years (IQR: 3.2–10.7) in our centre. We investigated parasystole in the patients who developed ventricular arrhythmia (VA) using 9886 ECGs, 280 Holter ECGs and 6391 implantable cardioverter defibrillator interrogation records. Classic parasystole was defined as three ventricular ectopic beats with the same morphology, occurring at integer-multiple intervals but with different coupling intervals (CI) on ECG. New parasystole was defined as two ventricular ectopic beats with a CI difference of more than 120 ms. We also analysed the correlation between inflammation sites and parasystole morphology observed on a 12-lead ECG. Results VA was identified in 95 patients (33.7%), and 22 developed VF (23.2%). Parasystole was observed in 12 of the 22 patients with VF (classic: 5, new: 7), 20 of 73 with ventricular tachycardia (classic: 5, new: 15) and 44 of 118 without VA (classic: 16, new: 28). Parasystole was significantly more common in the VF group than in the non-VF group (p=0.049). The site of inflammation observed on ¹⁸ F-fluorodeoxyglucose positron emission tomography performed within 3 months after the development of VA and the origin of parasystole matched in all four patients with VF who had 12-lead ECG records of parasystole. Inflammation was correlated with the origin of parasystole. Conclusion Ventricular parasystole was detected in one-third of patients with CS in this study, especially those with VF. The presence of parasystole and inflammation may predict the occurrence of VF in patients with CS.