Deep Learning Models for Predicting Left Heart Abnormalities From Single-Lead Electrocardiogram for the Development of Wearable Devices.

BACKGROUND: Left heart abnormalities are risk factors for heart failure. However, echocardiography is not always available. Electrocardiograms (ECGs), which are now available from wearable devices, have the potential to detect these abnormalities. Nevertheless, whether a model can detect left heart abnormalities from single Lead I ECG data remains unclear.Methods and Results: We developed Lead I ECG models to detect low ejection fraction (EF), wall motion abnormality, left ventricular hypertrophy (LVH), left ventricular dilatation, and left atrial dilatation. We used a dataset comprising 229,439 paired sets of ECG and echocardiography data from 8 facilities, and validated the model using external verification with data from 2 facilities. The area under the receiver operating characteristic curves of our model was 0.913 for low EF, 0.832 for wall motion abnormality, 0.797 for LVH, 0.838 for left ventricular dilatation, and 0.802 for left atrial dilatation. In interpretation tests with 12 cardiologists, the accuracy of the model was 78.3% for low EF and 68.3% for LVH. Compared with cardiologists who read the 12-lead ECGs, the model's performance was superior for LVH and similar for low EF. CONCLUSIONS: From a multicenter study dataset, we developed models to predict left heart abnormalities using Lead I on the ECG. The Lead I ECG models show superior or equivalent performance to cardiologists using 12-lead ECGs.

Clinical feasibility of endovascular recanalization with intravascular ultrasound-guided wiring for chronic total occlusion of below-the-knee arteries.

BACKGROUND: Revascularization with endovascular therapy (EVT) for complex below-the-knee (BTK) chronic total occlusion (CTO) remains a challenging problem. The Japanese-BTK (J-BTK) CTO score is reported as an indicator of the difficulty of BTK CTO, with the guidewire (GW) passage success rate decreasing as the grade increases. We previously reported an effective GW crossing method for the intravascular ultrasound (IVUS)-guided parallel wiring of complex BTK CTO. In this study, we investigated the feasibility of EVT using IVUS-guided wiring for BTK CTO. MATERIALS AND METHODS: This single center, retrospective study analyzed 65 consecutive BTK CTO vessels in which IVUS-guided wiring was attempted after the failure of a conventional antegrade wiring approach from November 2020 to November 2022. The primary endpoint was the clinical success of the target CTO vessel. The secondary endpoints were the GW success rate per grade based on the J-BTK CTO score, number of GW used for CTO crossing, fluoroscopy time, and complications. RESULTS: Target vessels were the anterior tibial artery (66.2% of cases), peroneal artery (9.2%), and posterior tibial artery (24.6%). Blunt type CTO entry was performed in 55.4% of cases, calcification of entry was observed in 24.6% of cases, the mean occlusion length was 228.2 ± 93.7 mm, mean reference vessel diameter was 2.1 ± 0.71 mm, and outflow was absent in 38.5% of cases. J-BTK CTO scores of 0/1 (grade A), 2/3 (grade B), 4/5 (grade C), and 6 (grade D) were seen in 18.5%, 43.1%, 36.3%, and 1.5% of cases, respectively. The clinical success rate was 95.4%. The GW success rate by J-BTK CTO grade was as follows: grade A (100%), B (100%), C (91.7%), and D (0%). The mean number of GW used was 3.4 ± 1.4, the mean fluoroscopy time was 72.3 ± 32.5 min, and complications occurred in 7.7% of cases. CONCLUSION: This study showed a very high clinical success rate despite the difficulty of BTK CTO. IVUS-guided EVT might be a feasible strategy for complex BTK CTO.

Right versus left coronary artery involvement in patients with type A acute aortic dissection.

BACKGROUND: Type A acute aortic dissection (AAD) complicated by coronary malperfusion is a life-threatening disease. In the present study, we compared the clinical characteristics and prognostic impact of treatment strategies including surgical treatment and percutaneous coronary intervention (PCI) in type A AAD patients with RCA and LCA involvement. METHODS: This multicenter registry included 220 patients with type A AAD and either RCA or LCA involvement. Treatment strategies were left to treating physicians. The primary endpoint was in-hospital death. RESULTS: Of 220 patients, 115 (52.3%) and 105 (47.7%) had RCA and LCA involvement. Patients with LCA involvement were more1 likely to present with Killip class IV on admission than those with RCA involvement. Coronary angiography was performed in 52 of 220 (23.6%) patients, among whom 39 (75.0%) underwent subsequent PCI. During the hospitalization, 93 (42.3%) patients died. Patients with LCA involvement had an increased risk of in-hospital mortality compared to those with RCA involvement (54.3% vs. 31.3%, p < 0.001). In patients with RCA involvement, multivariable analysis identified Killip class IV and no surgical treatment as predictors of in-hospital death, while PCI and surgical treatment were indicated as factors associated with lower in-hospital mortality in patients with LCA involvement. CONCLUSIONS: The rates of RCA and LCA involvement were similar in type A AAD. Immediate PCI as a bridge to subsequent surgical treatment might improve survival in patients with type A AAD complicated by coronary malperfusion, especially in those with LCA involvement.

CHA2DS2-VASc score is a useful-predictor of not prognosis but coronary-arteriosclerosis in chronic atrial-fibrillation compared with CHADS2 score: a two-center study of 320-slice CT, part 2.

BACKGROUND: The aim of this study is to predict the risk of coronary-arteriosclerosis and prognosis in subjects with chronic-atrial-fibrillation (CAF) using the CHADS2 and CHA2DS2-VASc scores by 320-slice-CT and invasive-coronary-angiography (ICA) in a two-center-study. METHODS: 53 CAF subjects who underwent 320-slice-CT and ICA within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two-institutes were analyzed. CT and ICA data were transferred to the analysis-center and were analyzed by cardiologists. RESULTS: Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis were significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However there were no-significant differences in the Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis evaluated by 320-slice CT between the subjects with CHADS2 score ≥ 2 and <2. Frequency of >50% coronary artery stenosis by ICA was significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However, there were no-significant differences in the frequencies of >50% and >75% coronary artery stenosis by ICA between the subjects with CHADS2 score ≥ 2 and <2. During a mean of 15.9 months, composite rate of cardiac death and heart failure did not differ between subjects with CHADS2 score ≥ 2 and score <2 and between subjects with CHA2DS2-VASc score ≥ 3 and score <3. CONCLUSIONS: The CHA2DS2-VASc score is a useful predictor of not prognosis but coronary-arteriosclerosis in subjects with CAF compared with CHADS2 score in this two-center-study.

A two center 320 slice CT study for evaluating coronary arteries in subjects with chronic atrial fibrillation: a comparison of prospective and retrospective ECG-gating acquisition.

PURPOSE: To compare diagnostic-accuracy of prospective and retrospective-ECG-gated acquisition in 320-slice-CT for detecting coronary-artery stenosis in subjects with chronic-atrial-fibrillation (CAF) in a two-center study. MATERIALS AND METHODS: 53 CAF subjects who underwent 320-slice-CT, and invasive-coronary-angiogram (ICA) within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two institutes were analyzed. In Institute-1, prospective-ECG-gated acquisition was routinely performed (N=33). In Institute-2, retrospective-ECG-gated acquisition was routinely performed (N=20). CT and ICA data were transferred to the analysis center and were analyzed by cardiologists blinded to the clinical-data. RESULTS: Prevalence of >50 and >75% on ICA was 79 and 61% in Institute-1, and 30 and 15% in Institute-2, respectively. In a patient-by-patient analysis, Institute-2 had higher negative-predictive-value (NPV) and accuracy of >75% stenosis on CT in predicting >75% stenosis on ICA. In a vessel-by-vessel analysis, there were no significant-differences of sensitivity, specificity, positive-predictive-value (PPV) and NPV of >50% stenosis on CT in predicting >50% stenosis on ICA between both institutes. But sensitivity, specificity, and NPV of >75% stenosis on CT in predicting >75% stenosis on ICA were significantly higher in Institute-2 than in Institute-1. This is mainly because of more severe coronary-artery disease including calcification in Institute-1; there might also have been an influence of differences in scanning and reconstruction methods. CONCLUSIONS: 320-slice-CT shows relatively high diagnostic-accuracy for the detection of significant coronary-artery stenosis compared with ICA even in CAF subjects, in a two-center analysis. Retrospective-ECG-gated acquisition in 320-slice-CT shows significantly higher diagnostic-accuracy than prospective-ECG-gated acquisition for detection of >75% coronary-artery stenosis.

Inhibitory effect of the class III antiarrhythmic drug nifekalant on HERG channels: mode of action.

Nifekalant is a class III antiarrhythmic drug that has been shown to be effective against ventricular tachyarrhythmias in experimental animals and humans. We examined the detailed electrophysiological effects of nifekalant on human-ether-a-go-go-related gene (HERG) channels expressed in Xenopus oocytes. Nifekalant inhibited the HERG current in a concentration-dependent manner with an IC(50) value of 7.9 microM although the drug did not inhibit the minK current in Xenopus oocytes, suggesting selective inhibition of the rapid component of the delayed rectifier K(+) current (I(Kr)) in cardiomyocytes. Nifekalant showed a higher binding affinity for the open state than for the inactive state of HERG channels. Nifekalant inhibited HERG channels in a frequency-dependent manner. The onset of the blockade was rapid but the recovery from the block was slow. Nifekalant modified the voltage dependence and kinetics of HERG channel gating. Thus, nifekalant inhibits HERG channels in a voltage-dependent and frequency-dependent manner, and the inhibitory effect may underlie the clinical efficacy of the drug against ventricular tachyarrhythmias.