Prognosis and recurrence in cardiac sarcoidosis: Serial assessment of BMIPP SPECT and FDG-PET

Incidence and Predictors of Relapse After Weaning Immune Suppressive Therapy in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a relapsing-remitting disease, and immune suppression (IS) is the mainstay of therapy. Predictors of relapse for patients with CS in remission are not well characterized. We assessed incidence of relapse in consecutive patients with CS treated with high-dose steroids and/or steroid-sparing agents (SSA) in our center from 2000 to 2020. Remission was defined as reaching maintenance therapy (no IS, SSA, and/or prednisone ≤5 mg/d) for ≥1 month. Relapse was defined as recurrence of CS syndrome requiring IS intensification: heart failure, ventricular arrhythmia, decrease in left ventricular ejection fraction, or increased disease burden on imaging. Among 68 patients, the mean age was 50.7±9.0 years; 25 (37%) were women, and 32 (47%) were Black. In total, 59 patients (87%) reached remission. Over a median follow-up of 39.5 months (interquartile range 17.6, 92.5), 28 (48%) relapsed. Greater percentage of late gadolinium enhancement (LGE) on pretreatment magnetic resonance imaging corresponded with increased likelihood of relapse (odds ratio 1.396 per 5% increase [95% confidence interval (CI) 1.04 to 1.88]; p = 0.028). LGE ≥11% predicted elevated risk of relapse (adjusted odds ratio 4.998 [1.34 to 18.64]; p = 0.017). Shorter time to relapse was observed with isolated CS (adjusted hazard ratio 4.084 [1.44,11.56]; p = 0.008) and LGE ≥11% (adjusted hazard ratio 3.007 [1.01, 8.98]; p = 0.049). Approximately 1 in 2 patients with CS in remission experienced relapse. Greater burden of LGE on cardiac magnetic resonance imaging and isolated CS are associated with greater risk of relapse. Future work is needed to refine risk stratification for relapse and to optimize surveillance strategies on the basis of the burden of disease.

Linking cardiac and extracardiac sarcoidosis and their clinical outcome: 18F-FDG PET/CT analysis in patients with systemic cardiac sarcoidosis

OBJECTIVE

To clarify the link between cardiac sarcoidosis (CS) and extra-CS (ECS) in systemic CS (SCS) patients in terms of extent and clinical outcome by serial FDG-PET/CT.

METHODS

Thirty-five SCS patients treated for > 2 years were enrolled in this study. In the overall analysis, patient-based comparisons of the complete resolution (CR) and recurrence rate between CS and ECS lesions were performed. Then, subgroup analyses were performed according to the extent (mono- vs. multi-organ ECS group) and clinical outcome (stable vs. unstable ECS group) of ECS. Pre-treatment cardiac FDG uptake was compared between the mono- and multi-organ ECS groups. The rates of CR, recurrence, and major adverse cardiac events (MACE) were compared between the two groups.

RESULTS

The CR rate was significantly higher in CS than ECS lesions [77.1% (27/35) vs. 48.5% (17/35), p = 0.01], whereas recurrence rates were similar between CS and ECS [40.7% (11/27) vs. 58.8% (10/17)]. Both the mono- and multi-organ ECS groups showed similar SUV_max, cardiac metabolic volume, and cardiac metabolic activity in the pre-treatment condition. The CR rates were similar between the mono- and multi-organ ECS groups [71.4% (15/21) vs. 85.7% (12/14)], but the recurrence rate was significantly lower in the multi-organ ECS group [60.0% (9/15) vs. 16.7% (2/12), p = 0.02]. The CR [71.4% (5/7) vs. 78.6% (22/28)] and recurrence rates [60.0% (3/5) vs. 36.3% (8/22)] were not significantly different between the stable and unstable ECS groups. The occurrence of MACE was also not significantly different between the mono- and multi-organ ECS groups [19.0% (4/21) vs. 28.6% (4/14)] or between the stable and unstable ECS groups [42.9% (3/7) vs. 17.8% (5/28)].

CONCLUSIONS

CS lesions respond to treatment better than ECS lesions, and the extent and clinical outcome of ECS lesion are not linked with those of CS lesions.

Prognostic Value of Cardiac MRI and FDG PET in Cardiac Sarcoidosis: A Systematic Review and Meta-Analysis

Background There is no consensus regarding the relative prognostic value of cardiac MRI and fluorodeoxyglucose (FDG) PET in cardiac sarcoidosis. Purpose To perform a systematic review and meta-analysis of the prognostic value of cardiac MRI and FDG PET for major adverse cardiac events (MACE) in cardiac sarcoidosis. Materials and Methods In this systematic review, MEDLINE, Ovid Epub, CENTRAL, Embase, Emcare, and Scopus were searched from inception until January 2022. Studies that evaluated the prognostic value of cardiac MRI or FDG PET in adults with cardiac sarcoidosis were included. The primary outcome of MACE was assessed as a composite including death, ventricular arrhythmia, and heart failure hospitalization. Summary metrics were obtained using random-effects meta-analysis. Meta-regression was used to assess covariates. Risk of bias was assessed using the Quality in Prognostic Studies, or QUIPS, tool. Results Thirty-seven studies were included (3489 patients with mean follow-up of 3.1 years ± 1.5 [SD]); 29 studies evaluated MRI (2931 patients) and 17 evaluated FDG PET (1243 patients). Five studies directly compared MRI and PET in the same patients (276 patients). Left ventricular late gadolinium enhancement (LGE) at MRI and FDG uptake at PET were both predictive of MACE (odds ratio [OR], 8.0 [95% CI: 4.3, 15.0] [P < .001] and 2.1 [95% CI: 1.4, 3.2] [P < .001], respectively). At meta-regression, results varied by modality (P = .006). LGE (OR, 10.4 [95% CI: 3.5, 30.5]; P < .001) was also predictive of MACE when restricted to studies with direct comparison, whereas FDG uptake (OR, 1.9 [95% CI: 0.82, 4.4]; P = .13) was not. Right ventricular LGE and FDG uptake were also associated with MACE (OR, 13.1 [95% CI: 5.2, 33] [P < .001] and 4.1 [95% CI: 1.9, 8.9] [P < .001], respectively). Thirty-two studies were at risk for bias. Conclusion Left and right ventricular late gadolinium enhancement at cardiac MRI and fluorodeoxyglucose uptake at PET were predictive of major adverse cardiac events in cardiac sarcoidosis. Limitations include few studies with direct comparison and risk of bias. Systematic review registration no. CRD42021214776 (PROSPERO) © RSNA, 2023 Supplemental material is available for this article.

Assessment of Cardiac Sarcoidosis: FDG PET and BMIPP SPECT

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) is an inflammatory disease of unknown etiology that can lead to life-threatening arrhythmias, heart failure, and death. Advanced cardiac imaging modalities have improved the clinician's ability to detect this disease. The purpose of this review is to discuss the recent evidence of cardiac metabolic imaging as assessed by [¹⁸F]FDG PET and [¹²³I]BMIPP SPECT in the evaluation of CS patients.

RECENT FINDINGS

[¹⁸F]FDG PET is the gold standard to identify myocardial inflammation. [¹²³I]BMIPP SPECT can uncover early myocardial damage as well as advanced stages of CS when fibrosis prevails. In presence of inflammation, myocardial [¹⁸F]FDG uptake is increased, but in contrast, BMIPP myocardial uptake is reduced or even suppressed. Thus, a complementary role of cardiac metabolic imaging by [¹⁸F]FDG PET and BMIPP SPECT has been proposed to detect the whole spectrum of CS. [¹⁸F]FDG PET is considered an important tool to improve the diagnosis and optimize the management of CS. The role of [¹²³I]BMIPP SPECT in diagnosing CS is still under investigation. Further studies are needed to evaluate the clinical utility of combined cardiac metabolic imaging in the diagnosis, prognosis, and for selecting treatments in CS patients.

Sarcoidosis: Updates on therapeutic drug trials and novel treatment approaches

Sarcoidosis is a systemic granulomatous inflammatory disease of unknown etiology. It affects the lungs in over 90% of patients yet extra-pulmonary and multi-organ involvement is common. Spontaneous remission of disease occurs commonly, nonetheless, over 50% of patients will require treatment and up to 30% of patients will develop a chronic progressive non-remitting disease with marked pulmonary fibrosis leading to significant morbidity and death. Guidelines outlining an immunosuppressive treatment approach to sarcoidosis were recently published, however, the strength of evidence behind many of the guideline recommended drugs is weak. None of the drugs currently used for the treatment of sarcoidosis have been rigorously studied and prescription of these drugs is often based on off-label” indications informed by experience with other diseases. Indeed, only two medications [prednisone and repository corticotropin (RCI) injection] currently used in the treatment of sarcoidosis are approved by the United States Food and Drug Administration. This situation results in significant reimbursement challenges especially for the more advanced (and often more effective) drugs that are favored for severe and refractory forms of disease causing an over-reliance on corticosteroids known to be associated with significant dose and duration dependent toxicities. This past decade has seen a renewed interest in developing new drugs and exploring novel therapeutic pathways for the treatment of sarcoidosis. Several of these trials are active randomized controlled trials (RCTs) designed to recruit relatively large numbers of patients with a goal to determine the safety, efficacy, and tolerability of these new molecules and therapeutic approaches. While it is an exciting time, it is also necessary to exercise caution. Resources including research dollars and most importantly, patient populations available for trials are limited and thus necessitate that several of the challenges facing drug trials and drug development in sarcoidosis are addressed. This will ensure that currently available resources are judiciously utilized. Our paper reviews the ongoing and anticipated drug trials in sarcoidosis and addresses the challenges facing these and future trials. We also review several recently completed trials and draw lessons that should be applied in future.