Machine learning-based detection of sleep-disordered breathing in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is often concomitant with sleep-disordered breathing (SDB), which can cause adverse cardiovascular events. Although an appropriate approach to SDB prevents cardiac remodelling, detection of concomitant SDB in patients with HCM remains suboptimal. Thus, we aimed to develop a machine learning-based discriminant model for SDB in HCM. METHODS: In the present multicentre study, we consecutively registered patients with HCM and performed nocturnal oximetry. The outcome was a high Oxygen Desaturation Index (ODI), defined as 3% ODI >10, which significantly correlated with the presence of moderate or severe SDB. We randomly divided the whole participants into a training set (80%) and a test set (20%). With data from the training set, we developed a random forest discriminant model for high ODI based on clinical parameters. We tested the ability of the discriminant model on the test set and compared it with a previous logistic regression model for distinguishing SDB in patients with HCM. RESULTS: Among 369 patients with HCM, 228 (61.8%) had high ODI. In the test set, the area under the receiver operating characteristic curve of the discriminant model was 0.86 (95% CI 0.77 to 0.94). The sensitivity was 0.91 (95% CI 0.79 to 0.98) and specificity was 0.68 (95% CI 0.48 to 0.84). When the test set was divided into low-probability and high-probability groups, the high-probability group had a higher prevalence of high ODI than the low-probability group (82.4% vs 17.4%, OR 20.9 (95% CI 5.3 to 105.8), Fisher's exact test p<0.001). The discriminant model significantly outperformed the previous logistic regression model (DeLong test p=0.03). CONCLUSIONS: Our study serves as the first to develop a machine learning-based discriminant model for the concomitance of SDB in patients with HCM. The discriminant model may facilitate cost-effective screening tests and treatments for SDB in the population with HCM.

Model for classification of heart failure severity in patients with hypertrophic cardiomyopathy using a deep neural network algorithm with a 12-lead electrocardiogram.

OBJECTIVES: In hypertrophic cardiomyopathy (HCM), specific ECG abnormalities are observed. Therefore, ECG is a valuable screening tool. Although several studies have reported on estimating the risk of developing fatal arrhythmias from ECG findings, the use of ECG to identify the severity of heart failure (HF) by applying deep learning (DL) methods has not been established. METHODS: We assessed whether data-driven machine-learning methods could effectively identify the severity of HF in patients with HCM. A residual neural network-based model was developed using 12-lead ECG data from 218 patients with HCM and 245 patients with non-HCM, categorised them into two (mild-to-moderate and severe) or three (mild, moderate and severe) severities of HF. These severities were defined according to the New York Heart Association functional class and levels of the N-terminal prohormone of brain natriuretic peptide. In addition, the patients were divided into groups according to Kansas City Cardiomyopathy Questionnaire (KCCQ)-12. A transfer learning method was applied to resolve the issue of the low number of target samples. The model was trained in advance using PTB-XL, which is an open ECG dataset. RESULTS: The model trained with our dataset achieved a weighted average F1 score of 0.745 and precision of 0.750 for the mild-to-moderate class samples. Similar results were obtained for grouping based on KCCQ-12. Through data analyses using the Guided Gradient Weighted-Class Activation Map and Integrated Gradients, QRS waves were intensively highlighted among true-positive mild-to-moderate class cases, while the highlighted part was highly variable among true-positive severe class cases. CONCLUSIONS: We developed a model for classifying HF severity in patients with HCM using a deep neural network algorithm with 12-lead ECG data. Our findings suggest that applications of this DL algorithm for using 12-lead ECG data may be useful to classify the HF status in patients with HCM.

Diagnostic value of heart-to-mediastinum ratio in 99mTc-pyrophospate SPECT/CT for transthyretin cardiac amyloidosis.

BACKGROUND: In transthyretin cardiac amyloidosis (ATTR-CA), 99mTc-pyrophosphate myocardial scintigraphy (99mTc-PYP) is a diagnostic tool that utilizes visual and quantitative evaluation. However, false positive cases can occur because of tracer accumulation in the blood. We investigated the effectiveness of the heart-to-mediastinum (H/M) ratio of 99mTc-PYP in ATTR-CA diagnosis. METHODS: We retrospectively included 164 patients who underwent 99mTc-PYP single-photon emission computed tomography/computed tomography between March 2019 and January 2022. The diagnostic accuracy of ATTR-CA was examined by the heart-to-contralateral lung (H/CL) and H/M ratio calculated at 3 hours post-tracer administration. RESULTS: After the exclusion of patients who did not undergo endomyocardial biopsy, 30 patients (15 each with ATTR-CA and without ATTR-CA) were included. The receiver operating characteristic curve used to distinguish ATTR-CA from non-ATTR-CA patients revealed an area under the curve of 0.986 and 0.943, respectively. A H/M ratio of > 1.41 identified ATTR-CA patients with a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100, 93.3, 93.3, and 100%, respectively. Conversely, an H/CL ratio of > 1.3 identified ATTR-CA patients with 100% sensitivity, 40.0% specificity, 62.5% PPV, and 100% NPV. CONCLUSION: The H/M ratio obtained at 3 hours post-injection has the potential to be a novel indicator for ATTR-CA.

Current status and recent changes in blood pressure and dietary salt consumption in Japanese individuals.

Purpose: Treatment of hypertension has recently shown remarkable advances. It is quite important to survey the current general status of blood pressure (BP) and recent changes to verify whether people are benefitting from these advances. The present study aimed to investigate the current status of, and recent changes in, BP, the prevalence and treatment rate of hypertension, the achievement rate of target BP, and salt intake in Japanese individuals. Methods: Recent changes in salt intake as well as BP, the prevalence and treatment rate of hypertension, and the rate of achievement of target BP were investigated in participants in our yearly physical checkup program from 2009 to 2018 (n = 79,789). Individual salt intake was assessed by estimating 24-hour urinary sodium excretion using a spot urine sample. Results: The prevalence of hypertension did not change, but the treatment rate of hypertension (from 64% to 75%) and the achievement rate of the target BP improved during the period (from 35% to 57%). BP decreased, prominently in hypertensive participants under antihypertensive treatment (from 133 ± 14/84 ± 9 to 128 ± 13/76 ± 10 mmHg). Salt intake did not decline noticeably during the 10 years of observation. Conclusions: The prevalence of hypertension did not change, but the treatment rate of hypertension and the achievement rate of the target BP improved during a recent 10-year period. These findings suggest that improved pharmacological management of hypertension resulted in a gradual reduction in BP levels, but lifestyle modification has not yet really taken root in the Japanese general population.

Central blood pressure predicts the development of hypertension in the general population.

Although elevated blood pressure results in arterial stiffening, the converse could also be true. Previous studies have suggested that increased arterial stiffness precedes the development of hypertension. Since central blood pressure is augmented following arterial stiffening, the predictive value of central blood pressure for detecting new-onset hypertension was investigated in the general population. A total of 7840 normotensive subjects (male, 4592; mean age, 51 years) were followed up for a median of 4 years, with the endpoint being the development of hypertension. During the actual follow-up period of 31636 person-years, hypertension developed in 2608 subjects. Kaplan-Meier analysis revealed an increase in the risk of hypertension across the quartiles of baseline central blood pressure (log-rank P < 0.001), with incidence rates of hypertension in the first, second, third, and fourth quartiles of 8.8%, 22.3%, 39.9%, and 63.2%, respectively. Multivariate Cox hazard analysis demonstrated an increased hazard ratio of incident hypertension across the quartiles after adjustment for possible factors. Repeating the multivariate Cox hazard analysis with central blood pressure as a continuous variable also identified central blood pressure at baseline as a significant predictor of new-onset hypertension (P < 0.001). These results suggest that central blood pressure is a significant predictor of new-onset hypertension in individuals without hypertension.

Colchicine therapy for deep vein thrombosis in a patient with vascular-type Behçet disease: A case report.

RATIONALE: Behçet Disease (BD) is a chronic inflammatory vasculitis with thrombogenicity and multisystem involvement. Deep vein thrombosis (DVT) in the lower extremities is the most frequent manifestation of vascular involvement in BD. The causes of thrombosis vary widely and include congenital predisposition and acquired factors, but of all the thrombosis, the cause is rarely BD. Furthermore, there are few reports of treatment for thrombosis in BD. PATIENT CONCERNS: We herein describe the case of an Asian male patient aged 40 years, admitted to our hospital for left leg pain, edema, and swelling. DIAGNOSES: We confirmed the DVT and pulmonary artery thrombosis (PAT) by contrast computed tomography angiogram. At the same time, the patient developed oral ulcerations and skin lesions consistent with BD. INTERVENTIONS: The patient was initially treated with anticoagulants. However, because the improvement of DVT was inadequate, we added colchicine in anticipation of anti-inflammatory effects. After that, anticoagulation was discontinued, and only colchicine was continuously prescribed. OUTCOMES: We observed an almost complete resolution of DVT and PAT with no recurrence of thrombosis for 6 months after discharge. LESSONS: This case shows us that we should consider BD as a differential diagnosis of DVT and that colchicine therapy is effective for inflammation-induced thrombosis in BD.

Intraventricular thrombus and severe mitral regurgitation in the acute phase of takotsubo cardiomyopathy: two case reports.

BACKGROUND: Takotsubo cardiomyopathy is characterized by chest symptoms, electrocardiographic changes, and new regional wall motion abnormality in the apical segment of the left ventricle in the absence of obstructive coronary artery disease. Particularly, apical ballooning is broadly recognized as the classic form of takotsubo cardiomyopathy. Although the prognosis of most patients with takotsubo cardiomyopathy is generally favorable, complications associated with the morphological features of transient apical ballooning are not uncommon. CASE PRESENTATION: We describe two cases of transient complications in postmenopausal patients with takotsubo cardiomyopathy. Intraventricular thrombus was observed in Asian patient 1, and severe mitral regurgitation was observed in Asian patient 2. These complications were confirmed by transthoracic echocardiography immediately after typical takotsubo cardiomyopathy with apical ballooning was diagnosed. Anticoagulant therapy with heparin and warfarin was continued for 1 week in patient 1. After the therapy, complete resolution of the apical thrombus and recovery of systolic function of the left ventricle was observed by follow-up transthoracic echocardiography. In patient 2, transthoracic echocardiography indicated significant mitral regurgitation, which was caused by left ventricular tethering of the anterior mitral leaflet rather than left ventricular outflow tract obstruction or systolic anterior motion. Because the hemodynamic stability in patient 2 had been preserved, she was managed with conservative treatment. After approximately 1 month, follow-up transthoracic echocardiography revealed that mitral regurgitation had almost disappeared with complete resolution of left ventricular wall motion abnormalities. CONCLUSIONS: The presented cases indicated that important complications, such as intraventricular thrombus and severe mitral regurgitation, are associated with takotsubo cardiomyopathy in the acute phase. Because these complications are risk factors for developing a thromboembolic event or heart failure and/or pulmonary edema, timely and accurate identification of these complications is critical to achieving optimal clinical outcomes in patients with takotsubo cardiomyopathy.

Effect of combined therapy with catheter-directed thrombolysis and factor Xa inhibitor for inferior vena cava thrombosis: A case report.

RATIONALE: Inferior vena cava (IVC) thrombosis is an under-recognized entity that is associated with a mortality rate approaching twice that of lower extremity deep venous thrombosis (DVT). Thrombolytic therapy not only results in greater lysis, but also results in higher complication rates than anticoagulation alone. Catheter-directed thrombolysis (CDT), which is effective in accomplishing local resolution whilst reducing bleeding complications, has been established as an alternative treatment for patients with extensive DVT. PATIENT CONCERNS: We report the case of a 70-year-old man who was admitted due to warmness, pain, and swelling in his left leg and a feeling of gait disturbance. DIAGNOSES: Contrast-enhanced computed tomography and venous ultrasonography revealed a pulmonary embolism and extensive DVT spreading to the IVC. INTERVENTIONS: First, the patient was treated with fondaparinux. Since this was inadequate, he underwent CDT using a Fountain infusion catheter. Then, CDT was switched to direct oral anticoagulant (DOAC) treatment. OUTCOMES: Both CDT and subsequent DOAC treatments dramatically improved the DVT. His subjective symptoms have disappeared, and no recurrence of thrombosis has been identified. LESSONS: The present case showed the therapeutic effect of CDT, which preceded DOAC treatment, on an extensive DVT.