Utility of new FDG-PET/CT guidelines for diagnosing cardiac sarcoidosis in patients with implanted cardiac pacemakers for atrioventricular block

Diagnosing cardiac sarcoidosis (CS), especially in isolated cases, is challenging, particularly due to the limitations of endomyocardial biopsy, leading to potential undiagnosed cases in pacemaker-implanted patients. This study aims to provide real world findings to support new guideline for CS using 18F-fluoro-deoxyglucose positron-emission tomography computed tomography (FDG-PET/CT) which give a definite diagnosis of isolated CS (iCS) without histological findings. We examined consecutive patients with cardiac pacemakers for atrioventricular block (AV-b) attending our outpatient pacemaker clinic. The patients underwent periodical follow-up echocardiography and were divided into two groups according to echocardiographic findings: those with suspected CS and those without suspected CS. Patients suspected of having nonischemic cardiomyopathy underwent FDG-PET/CT for CS diagnosis. We investigated the utility of the new guideline for CS using FDG-PET/CT. Among the 272 patients enrolled, 97 patients were implanted with cardiac pacemakers for AV-b. Twenty-two patients were suspected of having CS during a median observation period of 5.4 years after pacemaker implantation. Of these, one did not consent, and nine of 21 cases (43%) were diagnosed with definite CS according to the new guidelines. Five of these nine patients were diagnosed with iCS using FDG-PET/CT. The number of patients diagnosed with definite CS using the new guidelines tended to be approximately 2.3 times that of the conventional criteria (p = 0.074). Three of the nine patients underwent steroid treatment. The composite outcome, comprising all-cause death, heart failure hospitalization, and a substantial reduction in left ventricular ejection fraction, were significantly lower in patients receiving steroid treatment compared to those without steroid treatment (p = 0.048). The utilization of FDG-PET/CT in accordance with the new guidelines facilitates the diagnosis of CS, including iCS, resulting in approximately 2.3 times as many diagnoses of CS compared to the conventional criteria. This guideline has the potential to support the early identification of iCS and may contribute to enhancing patient clinical outcomes.

The Mechanism and Natural History of Mitral Regurgitation in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is an infl/ammatory cardiomyopathy that can present with mitral regurgitation (MR), but few studies describe the mechanisms and natural history of MR in CS. We queried an institutional registry of 512 patients with CS for moderate or greater MR at diagnosis. Baseline demographic and echocardiography (TTE) data were collected. MR was classified by Carpentier type. Positron emission tomography was analyzed for 2-deoxy-2-[fluorine-18] fluoro-d-glucose (FDG) avidity of anterolateral and posteromedial papillary muscles. Follow-up TTE and positron emission tomography imaging of patients treated with immunosuppression was analyzed for MR severity and FDG avidity changes. Fifty-four patients were identified. Mean left ventricular ejection fraction was 39.3%, effective regurgitant orifice 0.34 cm2, and MR regurgitant volume 46.3 ml. Carpentier type I was the most common MR mechanism (46.3%). Forty-one patients had follow-up TTE (median follow-up 1.7 years, interquartile range 2.6 years). Evaluating preprocedural follow-up TTE only, MR severity was significantly reduced, with 37% of patients showing reduction by at least 1 severity grade (p = 0.04). With postprocedural TTE included, 61% of patients showed alleviation of MR severity with mean decrease in grade - 0.98 (p <0.001). Sixty-eight percent of patients had anterolateral/posteromedial FDG avidity. Papillary muscle FDG avidity resolved in 80% of patients (n = 20, median follow-up 1.6 years, interquartile range 2.5 years). In conclusion, Carpentier type I functional MR is the most common MR mechanism in CS. MR severity and papillary muscle FDG avidity decrease after treatment, and MR resolution is further strengthened by procedural intervention in a minority of patients, suggesting an overall favorable natural history of MR in CS.

Sarcoid Heart Disease: Review of Current Knowledge

Sarcoidosis is a granulomatous disease with the potential of multiple organ system involvement and its etiology remains unknown. Cardiac involvement is associated with worse clinical outcome, and has been reported to be 20-30% in white and as high as 58% in Japanese populations with sarcoidosis. Clinical manifestations of cardiac sarcoidosis highly depend on the extent and location of granulomatous inflammation. The most frequent presentations include heart block, tachyarrhythmia, or heart failure. Endomyocardial biopsy is the most specific diagnostic test, but has poor sensitivity due to often patchy involvement. The diagnosis of cardiac sarcoidosis remains challenging due to nonspecific imaging findings. Both 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and cardiac magnetic resonance imaging can be used to evaluate cardiac sarcoidosis, but evaluate different stages of the disease process. FDG-PET detects metabolically active inflammatory cells while cardiac magnetic resonance imaging with late gadolinium enhancement reveals areas of myocardial necrosis and fibrosis. Aggressive therapy of symptomatic cardiac sarcoidosis is often sought due to the high risk of sudden death and/or progression to heart failure. Prednisone 20-40 mg a day is the recommended initial treatment. In refractory or severe cases, higher doses of prednisone, 1-1.5 mg/kg/d (or its equivalent) and addition of a steroid-sparing agent have been utilized. Methotrexate is added most commonly. Long-term improvement has been reported with the use of a combination of weekly methotrexate and prednisone versus prednisone alone. After initiation of treatment, a cardiac FDG-PET scan may be performed 2-3 months later to assess treatment response.

Myocardial findings evaluated by echocardiography in cardiac sarcoidosis: A report of seven cases

Sarcoidosis is a multisystem granulomatous disease of unknown cause. With cardiac sarcoidosis (CS), patients represent a wide range of cardiac manifestations from subtle to overt morphological and functional abnormalities. The advent of ultrasound technologies has enabled to identify not only typical findings to CS such as basal thinning of the ventricular septum, but also subclinical myocardial alterations. Based on our recent experiences, we currently introduce a variety of myocardial manifestations evaluated by echocardiography on seven CS patients being selected. Most of the patients exhibited typical cardiac involvement and the remaining fairly unusual.

Cardiac sarcoidosis mimicking left ventricular noncompaction: An approach to acquired apical hypertrabeculation

A 65-year-old asymptomatic woman, who had been pathologically diagnosed with pulmonary sarcoidosis, was admitted for further evaluation of possible cardiac involvement. Her echocardiography demonstrated the development of apical hypertrabeculation that was not observed 5 years previously. Cardiac magnetic resonance imaging revealed late gadolinium enhancement in the same region. Gallium single photon-missioned computed tomography/computed tomography revealed high uptake. Therefore, the diagnosis of active cardiac sarcoidosis was established, and subsequent treatment with corticosteroid was initiated. No study regarding acquired left ventricular hypertrabeculation associated with cardiac sarcoidosis has been reported. The integrated multi-imaging modality approach helped in earlier recognition of cardiac sarcoidosis.

Cardiac sarcoidosis: diagnosis and management

Cardiac sarcoidosis is one of the most serious and unpredictable aspects of this disease state. Heart involvement frequently presents with arrhythmias or conduction disease, although myocardial infiltration resulting in congestive heart failure may also occur. The prognosis in cardiac sarcoidosis is highly variable, which relates to the heterogeneous nature of heart involvement and marked differences between racial groups. Electrocardiography and echocardiography often provide the first clue to the diagnosis, but advanced imaging studies using positron emission tomography and MRI, in combination with nuclear isotope perfusion scanning are now essential to the diagnosis and management of this condition. The identification of clinically occult cardiac sarcoidosis and the management of isolated and/or asymptomatic heart involvement remain both challenging and contentious. Corticosteroids remain the first treatment choice with the later substitution of immunosuppressive and steroid-sparing therapies. Heart transplantation is an unusual outcome, but when performed, the results are comparable or better than heart transplantation for other disease states. We review the epidemiology, developments in diagnostic techniques and the management of cardiac sarcoidosis.

Prevalence of echocardiographic features suggesting cardiac sarcoidosis in patients with pacemaker or implantable cardiac defibrillator

BACKGROUND AND OBJECTIVES

Basal septal thinning or localized aneurysmal dilatation without coronary artery disease has been described as a characteristic finding suggestive of cardiac sarcoidosis. We sought to assess the prevalence of this characteristic echocardiographic finding in patients with pacemaker (PM) or implantable cardiac defibrillator (ICD).

SUBJECTS AND METHODS

Echocardiography of patients who received PM or ICD were retrospectively analyzed. Patients with marked thinning and akinesia confined to the basal septum (type 1), or posterolateral wall resulting in localized aneurysmal outward bulging (type 2) without history of myocardial infarction or significant coronary stenosis were included for analysis.

RESULTS

Among 1,357 consecutive patients, 21 exhibited suggestive echocardiographic findings (type 1/2=15/6) with a mean ejection fraction of 37±11%. The prevalence was 1.2% in the PM group and 4.0% in the ICD group. Only 3 patients showed histologically confirmable sarcoidosis in lymph nodes, lung and heart, respectively. Endomyocardial biopsy was attempted in 6 patients, but failed to demonstrate sarcoidosis. The 1-, 2-, 4- and 6-year clinical events (death, cardiac transplantation and hospital admission)-free survival rates were 100%, 85.7±7.6%, 75.0±9.7% and 48.6±12.4%, respectively. During follow-up, two patients with PM underwent ICD implantation, and another underwent heart transplantation.

CONCLUSION

Prevalence of echocardiographic features suggesting prevalence of cardiac sarcoidosis is low in patients who underwent device implantation. However, considering the very low yield of endomyocardial biopsy and the rare extracardiac manifestations in cardiac sarcoidosis, characteristic echocardiographic findings could be an adjunctive diagnostic criterion in these patients.

Cardiac sarcoidosis

Cardiac sarcoidosis (CS) is a rare but potentially fatal condition that may present with a wide range of clinical manifestations including congestive heart failure, conduction abnormalities, and most notably, sudden death. Recent advances in imaging technology allow easier detection of CS, but the diagnostic guidelines with inclusion of these techniques have yet to be written. It has become clear that minimally symptomatic or asymptomatic cardiac involvement is far more prevalent than previously thought. Because of the potential life-threatening complications and potential benefit of treatment, all patients diagnosed with sarcoidosis should be screened for cardiac involvement. Patients with CS and symptoms such as syncope need an aggressive workup for a potentially life-threatening etiology, and often require implantable cardioverter-defibrillator therapy. CS patients without arrhythmic symptoms are still at risk for sudden death and may warrant an implantable cardioverter-defibrillator for primary prevention reasons. Although corticosteroids are regarded as the first-line drug of choice, therapy for CS is not yet standardized, and it is unclear at this point whether asymptomatic patients require therapy. Randomized clinical trials are clearly warranted to answer these very important patient care questions, and are endorsed fully by the authors.