Application of Magnetocardiography to Screen for Inflammatory Cardiomyopathy and Monitor Treatment Response.

Background Inflammatory cardiomyopathy is one of the most common causes of sudden cardiac death in young adults. Diagnosis of inflammatory cardiomyopathy remains challenging, and better monitoring tools are needed. We present magnetocardiography as a method to diagnose myocardial inflammation and monitor treatment response. Methods and Results A total of 233 patients were enrolled, with a mean age of 45 (±18) years, and 105 (45%) were women. The primary analysis included 209 adult subjects, of whom 66 (32%) were diagnosed with inflammatory cardiomyopathy, 17 (8%) were diagnosed with cardiac amyloidosis, and 35 (17%) were diagnosed with other types of nonischemic cardiomyopathy; 91 (44%) did not have cardiomyopathy. The second analysis included 13 patients with inflammatory cardiomyopathy who underwent immunosuppressive therapy after baseline magnetocardiography measurement. Finally, diagnostic accuracy of magnetocardiography was tested in 3 independent cohorts (total n=23) and 1 patient, who developed vaccine-related myocarditis. First, we identified a magnetocardiography vector to differentiate between patients with cardiomyopathy versus patients without cardiomyopathy (vector of ≥0.051; sensitivity, 0.59; specificity, 0.95; positive predictive value, 93%; and negative predictive value, 64%). All patients with inflammatory cardiomyopathy, including a patient with mRNA vaccine-related myocarditis, had a magnetocardiography vector ≥0.051. Second, we evaluated the ability of the magnetocardiography vector to reflect treatment response. We observed a decrease of the pathologic magnetocardiography vector toward normal in all 13 patients who were clinically improving under immunosuppressive therapy. Magnetocardiography detected treatment response as early as day 7, whereas echocardiographic detection of treatment response occurred after 1 month. The magnetocardiography vector decreased from 0.10 at baseline to 0.07 within 7 days (P=0.010) and to 0.03 within 30 days (P<0.001). After 30 days, left ventricular ejection fraction improved from 42.2% at baseline to 53.8% (P<0.001). Conclusions Magnetocardiography has the potential to be used for diagnostic screening and to monitor early treatment response. The method is valuable in inflammatory cardiomyopathy, where there is a major unmet need for early diagnosis and monitoring response to immunosuppressive therapy.

Myocardial and Cardiocirculatory Reserve in Asymptomatic Aortic Stenosis and Preserved Ejection Fraction.

BACKGROUND AND AIM OF THE STUDY: Managing patients with asymptomatic severe aortic stenosis (AS) remains a major challenge. Myocardial as well as cardiocirculatory reserve have been hypothesized to predict outcome in patients with asymptomatic AS. METHODS: A total of 48 patients (indexed aortic valve area 0.39 +/- 0.12 cm2/m2; ejection fraction (EF) 67 +/- 7%) underwent spiroergometry and dobutamine stress echocardiography. Death or valve surgery served as a combined endpoint for follow up. RESULTS: Thirty-seven patients reached the endpoint after a mean of 756 days (range: 100-2146 days). Age- and gender-corrected univariate Cox proportional analysis revealed the presence of mild obstructive lung disease, stroke work loss (SWL), end-systolic diameter index, and E/Flow propagation velocity as the best predictive clinical, valvular, cardiostructural, and left ventricular filling pressure parameters, respectively. After inclusion of these parameters into a baseline multivariable Cox proportional hazard model, SWL (HR 1.21 per rise of 1 unit, CI 1.08-1.35, p = 0.0005) and female gender (HR 3.37, CI 1.50-7.59, p = 0.0044) were independently predictive. Similarly, the best-performing myocardial parameter, EF after dobutamine, was independently predictive (HR 0.75 per 5 units, CI 0.57-0.99, p = 0.035) after inclusion. The best-performing exercise capacity parameter, Watt(max), was of borderline significance (HR 0.93 per 5 units, CI 0.86-1.00, p = 0.0505). For each parameter, cut-off values were determined by time-dependent receiver-operator characteristics. The Kaplan-Meier curves of the patients above versus below the cut-offs differed significantly for SWL (p = 0.001), Wattm (p = 0.001), and gender (p = 0.013). CONCLUSION: Besides SWL and female gender, the EF after dobutamine as well as highest exercise stress intensity reached are helpful in determining the prognosis of asymptomatic patients with moderate-severe AS.

Aortic valve replacement in asymptomatic and symptomatic patients with preserved left ventricular ejection fraction.

BACKGROUND AND AIM OF THE STUDY: Patients with moderate-severe aortic stenosis (AS) who maintain that they have no symptoms pose a decision-making dilemma. In order to determine whether or not preoperative symptoms were related to outcomes in these patients, results were compared after aortic valve replacement (AVR) in asymptomatic and symptomatic AS patients with a preserved left ventricular ejection fraction (LVEF). METHODS: Twenty asymptomatic and 18 symptomatic AS patients were investigated retrospectively, with clinical and echocardiographic studies being performed before and at 610 +/- 409 days after AVR. The patients' cardiopulmonary function was monitored using spiroergometry. RESULTS: Symptomatic AS patients improved their exercise tolerance after surgery more than asymptomatic patients, although exercise tolerance and LVEF remained lower in symptomatic patients. On comparing all postoperative objective changes between the groups, a difference was observed only for aortic valve area index. Improvements in left ventricular structure, diastolic function, and filling pressures after AVR were similar in both groups. Systolic function, as assessed by tissue Doppler, was improved only in the symptomatic group. Regression analyses identified preoperative exercise tolerance as the strongest independent determinant of postoperative functional outcome. The postoperative LVEF was independently predicted by the preoperative LVEF and exercise tolerance. CONCLUSION: Asymptomatic patients with moderate-severe AS and preserved systolic function exhibited similar improvements in cardiac remodeling, diastolic function, and filling pressures following AVR, compared to symptomatic patients. Differences in exercise tolerance and systolic function observed preoperatively between these groups were decreased after AVR.