Non-invasive detection of cardiac allograft rejection among heart transplant recipients using an electrocardiogram based deep learning model.

Aims: Current non-invasive screening methods for cardiac allograft rejection have shown limited discrimination and are yet to be broadly integrated into heart transplant care. Given electrocardiogram (ECG) changes have been reported with severe cardiac allograft rejection, this study aimed to develop a deep-learning model, a form of artificial intelligence, to detect allograft rejection using the 12-lead ECG (AI-ECG). Methods and results: Heart transplant recipients were identified across three Mayo Clinic sites between 1998 and 2021. Twelve-lead digital ECG data and endomyocardial biopsy results were extracted from medical records. Allograft rejection was defined as moderate or severe acute cellular rejection (ACR) based on International Society for Heart and Lung Transplantation guidelines. The extracted data (7590 unique ECG-biopsy pairs, belonging to 1427 patients) was partitioned into training (80%), validation (10%), and test sets (10%) such that each patient was included in only one partition. Model performance metrics were based on the test set (n = 140 patients; 758 ECG-biopsy pairs). The AI-ECG detected ACR with an area under the receiver operating curve (AUC) of 0.84 [95% confidence interval (CI): 0.78-0.90] and 95% (19/20; 95% CI: 75-100%) sensitivity. A prospective proof-of-concept screening study (n = 56; 97 ECG-biopsy pairs) showed the AI-ECG detected ACR with AUC = 0.78 (95% CI: 0.61-0.96) and 100% (2/2; 95% CI: 16-100%) sensitivity. Conclusion: An AI-ECG model is effective for detection of moderate-to-severe ACR in heart transplant recipients. Our findings could improve transplant care by providing a rapid, non-invasive, and potentially remote screening option for cardiac allograft function.

Association of Pulmonary Hypertension and Monoclonal Gammopathy of Undetermined Significance.

Objective: To determine the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in patients with PH as well as precapillary PH. Methods: Olmsted County residents with PH, diagnosed between 1/1/1995 and 9/30/2017, were identified, and age and sex were matched to a normal control group. The PH group and normal control group were then cross-referenced with the Mayo Clinic MGUS database. Charts were reviewed to verify MGUS and PH. Heart catheterization data were then analyzed in these patients for reference to the gold standard for diagnosis. Results: There were 3419 patients diagnosed with PH by echocardiography between 1995 and 2017 in Olmsted County that met the criteria of our study. When the PH group (N = 3313) was matched to a normal control group (3313), a diagnosis of MGUS was significantly associated with PH 10.2% (OR = l.84 [95% CI 1.5-2.2], p < 0.001), compared with controls 5.8% based on echo diagnosis. Using heart catheterization data (484 patients), a diagnosis of MGUS was associated with PH 13.0% (OR = 3.94 [95% CI 2.28-6.82], p < 0.001). For pulmonary artery hypertension (N = 222), a diagnosis of MGUS was associated with PH at similar 12.2% (OR = 4.50 [95%CI 1.86-10.90], p < 0.001. Conclusions: There is a higher prevalence of MGUS in patients with PH and precapillary PH compared with normal controls. This association cannot be explained fully by other underlying diagnoses associated with PH. Assessing for this in patients with PH of unclear etiology may be reasonable in the workup of patients found to have PH.

Heart transplantation in Val142Ile mutation in the modern era: A single center experience.

Little is known about the post heart transplantation management of extra cardiac manifestations in patients with hereditary transthyretin amyloid cardiomyopathy (hATTR-CM) in the new era of disease modifying treatment for ATTR amyloidosis. This is a retrospective study of all patients with hATTR-CM associated with the Val142Ile variant who underwent heart transplantation (HT) from January 2014 to February 2022. All 10 patients with the Val142Ile mutation were successfully transplanted, with a 1 year survival post heart transplantation (HT) of 90%, comparable to an age, sex, and race matched cohort of patients transplanted for non-amyloid indications. However, 4 (40%) of these patients developed progressive extracardiac manifestations requiring initiation of TTR silencer therapy with the small interfering RNA (siRNA) drug patisiran, which was well tolerated with no significant side effects in this population. We recommend formal neurologic evaluation and assessment of extracardiac manifestations annually as part of routine post-transplant care, and disease modifying therapy, aimed at TTR stabilization or silencing, should be initiated in the context of previously untreated extracardiac manifestations or evidence of subclinical neuropathy to prevent progression.

Ventricular arrhythmia burden and implantable cardioverter-defibrillator outcomes in transthyretin cardiac amyloidosis.

BACKGROUND: As targeted treatments for amyloid transthyretin cardiomyopathy (ATTR-CM) are becoming available, we aim to characterize the rates of ventricular arrhythmias (VAs), implantable cardioverter-defibrillator (ICD) utilization, and their impact on survival. METHODS: This is a retrospective cohort study of 130 patients with ATTR-CM diagnosed at Emory University's Cardiac Amyloidosis Center between April 2012 and September 2020. VAs were defined as nonsustained or sustained ventricular tachycardia and ventricular fibrillation. RESULTS: Of 130 patients, 42 had wild-type disease (wtATTR) and 88 had hereditary variants (hATTR), most commonly Val122Ile (89%). At ATTR-CM diagnosis, 80 (62%) patients had EF ≤ 40% consistent with systolic heart failure. Of the 69 (53%) patients with documented VAs significantly higher rates occurred among those with EF ≤ 40% compared with EF > 40% (67% vs. 28%, p = .001). Thirty-two patients (25 hATTR, 7 wtATTR) had primary prevention ICDs implanted. Eight (25%) of these patients received appropriate ICD therapy while two (6%) experienced inappropriate therapy. Comparing patients with EF ≤ 35% with and without ICDs did not reveal any survival difference (3.3 ± 0.5 vs. 2.8 ± 0.4 years, p = .699). CONCLUSIONS: High rates of VAs and appropriate ICD therapy were found among a unique cohort of largely hereditary ATTR-CM patients with a high rate of systolic heart failure.

Circulating Neprilysin in Patients With Heart Failure and Preserved Ejection Fraction.

BACKGROUND: In heart failure with reduced ejection fraction (HFrEF), elevated soluble neprilysin (sNEP) levels are associated with an increased risk of cardiovascular death, and its inhibition with sacubitril/valsartan has improved survival. OBJECTIVES: This study sought to determine the relevance of sNEP as a biomarker in heart failure with preserved ejection fraction (HFpEF) and to compare circulating sNEP levels in patients with HFpEF with normal controls. METHODS: A case-control study was performed in 242 symptomatic patients with HFpEF previously enrolled in the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction (RELAX) and Nitrates's Effect on Activity Tolerance in Heart Failure With Preserved Ejection (NEAT-HFpEF) clinical trials and 891 asymptomatic subjects without HF or diastolic dysfunction (confirmed by NT-proBNP levels <200 pg/ml and echocardiography) who were enrolled in the Prevalence of Asymptomatic Left Ventricular Dysfunction study. sNEP was measured using a sandwich enzyme-linked immunosorbent assay (ELISA) in all subjects. RESULTS: Overall, sNEP levels were lower in HFpEF compared with controls (3.5 ng/ml; confidence interval [CI]: 2.5 to 4.8 vs. 8.5 ng/ml; CI: 7.2 to 10.0; p < 0.001). After adjusting for age, gender, body mass index (BMI), and smoking history, mean sNEP levels were also lower in HFpEF compared with controls (4.0 ng/ml [CI: 2.7 to 5.4] vs. 8.2 ng/ml [CI: 6.8 to 9.7]; p = 0.002). The cohorts were propensity matched based on age, BMI, diabetes, hypertension, smoking history, and renal function, and sNEP levels remained lower in HFpEF compared with controls (median 2.4 ng/ml [interquartile range: 0.6 to 27.7] vs. 4.9 ng/ml [interquartile range: 1.2 to 42.2]; p = 0.02). CONCLUSIONS: Patients with HFpEF on average have significantly lower circulating sNEP levels compared with controls. These findings challenge our current understanding of the complex biology of circulating sNEP in HFpEF.

Exuberant mitral annular calcification.

Mitral annular calcification (MAC) is a chronic, progressive process characterized by calcium deposition on the mitral valve annulus. There is no current grading system to relay the severity of MAC. The primary purpose of this study was to investigate the extreme end of the severity spectrum in order to describe "exuberant mitral annular calcification", and a retrospective chart review of all patients with exuberant mitral annulus calcification evaluated at Mayo Clinic Rochester between January 1996 and December 2014 was performed. This is the first study to define criteria of "exuberant mitral annular calcification", emphasizing the importance of identifying the extreme degree of mitral annular calcification.

Ultrasound-guided fine-needle aspiration biopsy of thyroid nodules in patients taking novel oral anticoagulants.

BACKGROUND: Ultrasound-guided fine-needle aspiration biopsy (USGFNAB) is the most accurate form of evaluation for thyroid nodules. Many patients with thyroid nodules who present for USGFNAB are on anticoagulant agents, including the novel oral anticoagulants (NOACs), for stroke prevention in atrial fibrillation or venous thrombosis prophylaxis. SUMMARY: There has been at least one retrospective study describing neck USGFNAB bleeding risks in patients on antithrombotic and/or anticoagulant agents. This study concluded that there was no major bleeding risk or increase in hematoma formation in patients on antithrombotic or anticoagulant agents while undergoing USGFNAB, and there was no need to discontinue these agents prior to the procedure. With the emergence of NOACs, further recommendations should be made for patients on these agents who will be undergoing USGFNAB for thyroid nodules. Currently, there are no published studies regarding patients on NOACs who undergo USGFNAB. CONCLUSIONS: It has previously been established that patients on historical anticoagulant agents do not need to discontinue therapy prior to minor procedures such as needle aspirations or dental procedures. Therefore, in patients currently taking dabigatran, rivaroxaban, or apixaban, it is concluded that it is reasonable and safe to continue the novel oral anticoagulant agents prior to USGFNAB of thyroid nodules without major risk of bleeding. This conclusion is based not only on the fact that minor procedures are considered safe in patients on NOACs, but also because patients on historical anticoagulant agents do not need to discontinue therapy prior to minor procedures.