Impact of cancer on the prevalence, management, and outcome of patients with chronic thromboembolic pulmonary hypertension.

INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) results from unresolved thrombotic obstruction of the pulmonary vasculature. Cancer is a known risk factor for CTEPH. This study aimed to determine the impact of cancer on the prevalence, management, and outcomes of patients with CTEPH. MATERIALS AND METHODS: In this retrospective study involving 99 patients sequentially diagnosed with CTEPH in our hospital, the prevalence of 10 comorbid conditions including a past history of cancer at the time of CTEPH diagnosis were calculated. RESULTS: Among the 99 patients, 17 (17%) had a history of cancer. Breast cancer (n = 6) was the most common cancer type, followed by gastrointestinal cancer (n = 3), uterine cancer (n = 2), and malignant lymphoma (n = 2). Between patients with and without cancer, there were no differences in the demographics, severity of CTEPH, and management; however, the 5-year survival rate was lower for patients with cancer (65%) than for those without (89%). In addition, patients with cancer had significantly worse survival than those without (p = 0.03 by log-rank test). During follow-up, nine patients developed cancer after the diagnosis of CTEPH. Among the 99 patients, 13 died during follow-up, 6 (46%) of whom died of cancer. CONCLUSIONS: 17% of our patients with CETPH were diagnosed with cancer, with breast and gastrointestinal tract cancers being the most common. Cancer comorbidity was associated with a poor prognosis and contributed to death in 46% of deceased patients. The impact of cancer on CTEPH should be further evaluated in the future.

Effects of obesity on CC16 and their potential role in overweight/obese asthma.

INTRODUCTION: Club cell secretory protein-16 (CC16) is a major anti-inflammatory protein expressed in the airway; however, the potential role of CC16 on overweight/obese asthma has not been assessed. In this study, we examined whether obesity reduces airway/circulatory CC16 levels using experimental and epidemiological studies. Then, we explored the mediatory role of CC16 in the relationship of overweight/obesity with clinical asthma measures. METHODS: Circulating CC16 levels were assessed by ELISA in three independent human populations, including two groups of healthy and general populations and asthma patients. The percentage of cells expressing club markers in obese vs. non-obese mice and human airways was determined by immunohistochemistry. A causal mediation analysis was conducted to determine whether circulatory CC16 acted as a mediator between overweight/obesity and clinical asthma measures. RESULTS: BMI was significantly and monotonously associated with reduced circulating CC16 levels in all populations. The percentage of CC16-expressing cells was reduced in the small airways of both mice and humans with obesity. Finally, mediation analysis revealed significant contributions of circulatory CC16 in the association between BMI and clinical asthma measures; 21.8% of its total effect in BMI's association with airway hyperresponsiveness of healthy subjects (p = 0.09), 26.4% with asthma severity (p = 0.030), and 23% with the required dose of inhaled corticosteroid (p = 0.042). In logistic regression analysis, 1-SD decrease in serum CC16 levels of asthma patients was associated with 87% increased odds for high dose ICS requirement (p < 0.001). CONCLUSIONS: We demonstrate that airway/circulating CC16, which is inversely associated with BMI, may mediate development and severity in overweight/obese asthma.

Prognostic value of phase analysis on gated single photon emission computed tomography in patients with cardiac sarcoidosis.

BACKGROUND: We aimed to determine the correlation between phase analysis, reflecting the heterogeneity of perfusion defects, and the dyssynchrony of the left ventricle wall motion, and adverse cardiac events in cardiac sarcoidosis (CS) patients. METHODS: Fifty-seven consecutive patients with diagnosed CS (64 [IQR 55-71] years old, 14 males), who underwent 18F-FDG PET/CT and ECG-gated SPECT, were studied. FDG PET was analysed to measure cardiac metabolic volume (CMV), and total lesion glycolysis (TLG). The SPECT findings, such as LVEF, Summed Rest Score (SRS), bandwidth (BW) were evaluated. RESULTS: The median of BW was 56° (IQR 40-95). BW showed a strong inverse correlation with LVEF (r = - 0.60, P < 0.0001), and positive correlation with SRS (r = 0.82, P < 0.0001). However, there were no significant correlations between BW and CMV or TLG. The Kaplan-Meier curves revealed a significantly higher rate of MACE in the high BW group (BW > 56°) than the low BW group (BW ≤ 56°) (15.1%/years vs. 4.4%/years, P = 0.025). In multivariable analysis, BW was a significant independent predictor of MACE (P = 0.015). CONCLUSION: Phase analysis on gated SPECT was a significant and independent predictor of MACE in patients with CS.

The rate of myocardial perfusion recovery after steroid therapy and its implication for cardiac events in cardiac sarcoidosis and primarily preserved left ventricular ejection fraction.

BACKGROUND: Sarcoidosis is a multisystemic disorder of unknown cause characterized by immune granuloma formation in the involved organs. Few studies have reported on the myocardial perfusion changes by immunosuppression therapy in cardiac sarcoidosis (CS). Additionally, the relationship between myocardial perfusion changes and prognosis is unknown. Therefore, this study aimed to clarify myocardial perfusion recovery after steroid therapy and its prognostic value for major adverse cardiac events (MACE) in patients with CS. METHODS AND RESULTS: Thirty-eight consecutive patients with CS {median age, 63 [interquartile range (IQR) 51-68] years; 10 men} underwent both 18F-fluorodeoxyglucose positron emission tomography/computed tomography (CT) and electrocardiography-gated single-photon emission CT (SPECT) pre- and post-steroid therapy. Patients with improved or preserved myocardial perfusion after post-therapy were defined as the recovery group and those with worsened myocardial perfusion as the non-recovery group. Twenty-six patients (68%) were categorized as the recovery group. MACE occurred in eight patients. The Kaplan-Meier curves revealed a significantly higher rate of MACE in the non-recovery group (17.4%/y vs 2.9%/y, P = 0.007). CONCLUSIONS: Myocardial perfusion was recovered by steroid therapy in 61% and preserved in 8% of patients. Myocardial perfusion recovery after steroid therapy was significantly associated with a low incidence of MACE.

18F-FMISO PET/CT detects hypoxic lesions of cardiac and extra-cardiac involvement in patients with sarcoidosis.

BACKGROUND: 18F-fluoromisonidazole (FMISO) is a hypoxia positron emission tomography (PET) tracer. Here, we evaluated cardiac and extra-cardiac sarcoidosis using both FMISO and 18F-fluorodeoxyglucose (FDG) PET/CT in a prospective cohort of patients with sarcoidosis. METHODS: Ten consecutive sarcoidosis patients with suspected cardiac involvement were prospectively enrolled. Each patient fasted overnight (for ≥ 18 hours) preceded by a low-carbohydrate diet before FDG PET/CT but not given special dietary instructions before the FMISO PET/CT scan. We visually and semiquantitatively assessed the uptakes of FMISO and FDG using the maximal standardized uptake value (SUVmax). The metabolic volume (MV) of FDG was calculated as the volume within the boundary determined by the threshold (mean SUV of blood pool × 1.5). RESULTS: Nine patients showed focal FDG uptake in the myocardium and were diagnosed with cardiac sarcoidosis. Among the patients with extra-cardiac lesions, FDG uptake was seen in 8 lymph nodes and 3 lung lesions. FMISO uptake was seen in the 7 cardiac (77.8%) and 6 extra-cardiac (54.5%) lesions. None of the patients showed physiological FMISO uptake in the myocardium. The SUVmax values of the lesions with FMISO uptake were higher than those of the lesions without FMISO uptake in both the cardiac (SUVmax: 9.9, IQR: 8.4-10.0 vs 7.3, IQR: 6.3-8.2) and non-cardiac lesions (SUVmax: 17.6, IQR: 14.5-19.3 vs 6.1, IQR: 5.9-6.2; P = 0.006). The MV values of the lesions with FMISO uptake were significantly higher than those of the lesions without FMISO uptake (111.3, IQR: 78.3-135.7 vs 6.4, IQR: 1.9-23.3; P = 0.0009). CONCLUSIONS: FMISO showed no physiological myocardial uptake and did not require special preparation. FMISO PET has the potential to detect hypoxic lesions in patients with sarcoidosis.

The assessment of left heart disease in patients with systemic sclerosis and pulmonary hypertension.

OBJECTIVES: Systemic sclerosis associated pulmonary arterial hypertension (SSc-PAH) is of clinical significance owing to its poor outcome. One of the explanations for the outcome is the co-presence of left heart disease (LHD). The aim of this study is to assess LHD phenotype in patients with SSc and pulmonary hypertension (PH). METHODS: This study included consecutive patients with SSc who underwent right heart catheterisation to diagnose PAH. Heart failure with preserved ejection fraction (HFpEF) was evaluated according to the recommendation of 6th WSPH and to the Framingham criteria. RESULTS: In total, 76 patients were enrolled in this study. Of them, 42 had PH (mPAP >20 mmHg) with a normal left ventricle ejection fraction (≥50%). Among the 42 patients, four and three patients were classified "HFpEF not excluded" and "HFpEF confirmed" whereas 10 had a clinical diagnosis of HFpEF according to 6th WSPH and Framingham criteria, respectively. These differences were due mainly to relatively low PAWP (<13 mmHg). By a combination of ROC curve and logistic regression analyses, left atrial dimension and left ventricular end-diastolic volume index assessed with echocardiography and cardiac MRI, respectively, had significantly higher predictive values for detecting the complication of HFpEF rather than PAWP. CONCLUSIONS: Morphological evaluation using echocardiography and cardiac MRI, compared with haemodynamic evaluation by PAWP, may better reflect the copresence of LHD phenotype in patients with SSc and PH. Our data would also indicate a limited elevation of PAWP in patients with SSc, PH and HFpEF.

Multi-Institutional Prospective Cohort Study of Patients With Pulmonary Hypertension Associated With Respiratory Diseases.

BACKGROUND: There is limited evidence for pulmonary arterial hypertension (PAH)-targeted therapy in patients with pulmonary hypertension associated with respiratory disease (R-PH). Therefore, we conducted a multicenter prospective study of patients with R-PH to examine real-world characteristics of responders by evaluating demographics, treatment backgrounds, and prognosis.Methods and Results:Among the 281 patients with R-PH included in this study, there was a treatment-naïve cohort of 183 patients with normal pulmonary arterial wedge pressure and 1 of 4 major diseases (chronic obstructive pulmonary diseases, interstitial pneumonia [IP], IP with connective tissue disease, or combined pulmonary fibrosis with emphysema); 43% of patients had mild ventilatory impairment (MVI), whereas 52% had a severe form of PH. 68% received PAH-targeted therapies (mainly phosphodiesterase-5 inhibitors). Among patients with MVI, those treated initially (i.e., within 2 months of the first right heart catheterization) had better survival than patients not treated initially (3-year survival 70.6% vs. 34.2%; P=0.01); there was no significant difference in survival in the group with severe ventilatory impairment (49.6% vs. 32.1%; P=0.38). Responders to PAH-targeted therapy were more prevalent in the group with MVI. CONCLUSIONS: This first Japanese registry of R-PH showed that a high proportion of patients with MVI (PAH phenotype) had better survival if they received initial treatment with PAH-targeted therapies. Responders were predominant in the group with MVI.

Right ventricular dimension index by cardiac magnetic resonance for prognostication in connective tissue diseases and pulmonary hypertension.

OBJECTIVES: Pulmonary hypertension (PH) in patients with CTD is a heterogeneous condition affected by left heart disease, chronic lung disease and thromboembolism as well as pulmonary vascular disease. Recent studies using cardiac magnetic resonance (CMR) have shown that right ventricular dysfunction is predictive for mortality in patients with PH, but limited to pulmonary arterial hypertension. This study aimed to analyse prognostic factors in PH-CTD. METHODS: This retrospective analysis comprised 84 CTD patients, including SSc, who underwent both CMR and right heart catheterization from 2008 to 2018. Demographics, laboratory findings, and haemodynamic and morphological parameters were extracted. The prognostic value of each parameter was evaluated by multivariate analysis using covariables derived from propensity score to control confounding factors. RESULTS: Of 84 patients, 65 had right heart catheterization-confirmed PH (54 pulmonary arterial hypertension, 11 non-pulmonary arterial hypertension). Nine out of these PH patients died during a median follow-up period of 25 months. In 65 patients with PH, right ventricular end-diastolic dimension index (RVEDDI) evaluated by CMR was independently associated with mortality (hazard ratio 1.24; 95% CI: 1.08-1.46; P = 0.003). In a receiver operating characteristic analysis, RVEDDI highly predicted mortality, with area under the curve of 0.87. The 0.5-2-year follow-up data revealed that RVEDDI in both survivors and non-survivors did not significantly change over the clinical course, leading to the possibility that an early determination of RVEDDI could predict the prognosis. CONCLUSION: RVEDDI simply evaluated by CMR could serve as a significant predictor of mortality in PH-CTD. A further validation cohort study is needed to confirm its usability.

Use of 18F-FDG PET/CT texture analysis to diagnose cardiac sarcoidosis.

PURPOSE: 18F-fluorodeoxyglocose positron emission tomography (FDG PET) plays a significant role in the diagnosis of cardiac sarcoidosis (CS). Texture analysis is a group of computational methods for evaluating the inhomogeneity among adjacent pixels or voxels. We investigated whether texture analysis applied to myocardial FDG uptake has diagnostic value in patients with CS. METHODS: Thirty-seven CS patients (CS group), and 52 patients who underwent FDG PET/CT to detect malignant tumors with any FDG cardiac uptake (non-CS group) were studied. A total of 36 texture features from the histogram, gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), gray-level zone size matrix (GLZSM) and neighborhood gray-level difference matrix (NGLDM), were computed using polar map images. First, the inter-operator and inter-scan reproducibility of the texture features of the CS group were evaluated. Then, texture features of the patients with CS were compared to those without CS lesions. RESULTS: Twenty-eight of the 36 texture features showed high inter-operator reproducibility with intraclass correlation coefficients (ICCs) over 0.80. In addition, 17 of the 36 showed high inter-scan reproducibility with ICCs over 0.80. The SUVmax showed no difference between the CS and non-CS group [7.36 ± 2.77 vs. 8.78 ± 4.65, p = 0.45, area under the curve (AUC) = 0.60]. By contrast, 16 of the 36 texture features could distinguish CS from non-CS grsoup with AUC > 0.80. Multivariate logistic regression analysis after hierarchical clustering concluded that long-run emphasis (LRE; P = 0.0004) and short-run low gray-level emphasis (SRLGE; P = 0.016) were significant independent factors that could distinguish between the CS and non-CS groups. Specifically, LRE was significantly higher in CS than in non-CS (30.1 ± 25.4 vs. 11.4 ± 4.6, P < 0.0001), with high diagnostic ability (AUC = 0.91), and had high inter-operator reproducibility (ICC = 0.98). CONCLUSIONS: The texture analysis had high inter-operator and high inter-scan reproducibility. Some of texture features showed higher diagnostic value than SUVmax for CS diagnosis. Therefore, texture analysis may have a role in semi-automated systems for diagnosing CS.

Randomized comparison between 2-link cell design biolimus A9-eluting stent and 3-link cell design everolimus-eluting stent in patients with de novo true coronary bifurcation lesions: the BEGIN trial.

The appropriate stent platform for treating coronary bifurcation lesions (CBLs) remains controversial. Previous bench tests have demonstrated the superiority of a 2-link cell design to 3-link cell design for creating inter-strut dilation at the side branch ostium. This randomized multicenter prospective BEGIN trial compared the biodegradable polymer-based biolimus A9-eluting stent (2-link BES) with the durable polymer-based cobalt chromium everolimus-eluting stent (3-link EES) in 226 patients with de novo CBLs. Patients with true bifurcations, defined as > 50% stenosis in the main vessel and side branch (SB) and an SB diameter > 2.25 mm, were enrolled. Guide wire re-crossing to the distal cell (near the carina) in the jailed SB and final kissing inflation were recommended. The SB angiographic endpoint was < 50% stenosis diameter. Left-main CBLs (13.5% vs. 13.0%) and 2-stent technique (30.6% vs. 22.6%) rates were similar. The primary endpoints (minimum lumen diameter at the SB ostium measured at an independent core laboratory at the 8-month follow-up) were comparable (1.64 ± 0.50 mm vs. 1.63 ± 0.51 mm, p = 0.976). There was no significant difference in composite outcomes of cardiac death, myocardial infarction, or target vascular revascularization at 12 months (7.4% vs. 8.0%, p = 0.894). Two-link BES and 3-link EES showed similar 8-month angiographic and 1-year clinical outcomes for true CBLs.

Reduced diffusing capacity for carbon monoxide predicts borderline pulmonary arterial pressure in patients with systemic sclerosis.

Early intervention in pulmonary arterial hypertension associated with systemic sclerosis (SSc) may improve its prognosis. We aimed to establish an algorithm to detect mean pulmonary artery pressure (mPAP) > 20 mmHg using non-invasive examinations in SSc patients by modifying the DETECT algorithm. This study included SSc patients who underwent right heart catheterization (RHC) in our hospital during 2010-2018. Following variables were assessed for performance to predict mPAP ≥ 25 mmHg or > 20 mmHg; anti-centromere or U1-RNP antibody, plasma BNP level, serum urate level, right axis deviation, forced vital capacity (FVC)/diffusing capacity for carbon monoxide (DLCO) ratio, and tricuspid regurgitation velocity. Of 58 patients enrolled in this study, 24 had mPAP of ≥ 25 mmHg and 9 had mPAP of 21-24 mmHg. Among variables tested, only FVC/DLCO elevated similarly in patients with mPAP of ≥ 25 mmHg (median 2.5) and those with mPAP of 21-24 mmHg (median 2.5) compared to those with mPAP of ≤ 20 mmHg (median 1.5). Given the particularly good correlation between DLCO and mPAP of > 20 mmHg, each variable was weighted according to its odds ratio and the total weighted score was calculated. The total weighted score exhibited a good predictive performance for mPAP of > 20 mmHg with its sensitivity of 87.5% and specificity of 92%. Among conventional risk factors for PAH, decreased DLCO may predict mPAP > 20 mmHg with priority in SSc patients. Weighting DLCO may improve the performance of screening algorithm for early SSc-PAH.

Vascular response to biolimus A-9 eluting stent in patients with shorter and prolonged dual antiplatelet therapy: optical coherence tomography sub-study of the NIPPON trial.

Dual antiplatelet therapy (DAPT) with thienopyridine and aspirin is the standard care for the prevention of stent thrombosis. However, the optimal duration and effect of the duration of DAPT on intra-stent thrombus (IS-Th) formation are unknown. The NIPPON study (Nobori Dual Antiplatelet Therapy as Appropriate Duration) was an open label, randomized multicenter, assessor-blinded, trial designed to demonstrate the non-inferiority of shorter (6-month) DAPT to prolonged (18-month) DAPT, after biolimus A9 eluting stent implantation in 3773 patients at 130 sites in Japan. Among them, 101 patients were randomly allocated for an optical coherence tomography (OCT) sub-study to assess the difference of local IS-Th formation between the two groups. In addition to standard OCT parameters, the number of IS-Th formed was counted in each target stent at 8 months. Baseline patient characteristics were not different between the 6- and 18-month groups. IS-Th was detected in 9.8% of the cases and the presence of IS-Th was not significantly different between the two groups (10.9% in 6-month vs. 9.1% in 12-month, P = 0.76). Furthermore, the number of IS-Th formed was not significantly different between the two groups. This OCT sub-study was in line with the main NIPPON study which demonstrated the non-inferiority of 6-month DAPT to 18-month DAPT. Shorter DAPT duration did not promote progressive IS-Th formation at the mid-term time point.

Delayed contrast-enhanced computed tomography in patients with known or suspected cardiac sarcoidosis: A feasibility study.

OBJECTIVES: To evaluate the diagnostic value of delayed contrast-enhanced computed tomography (DE-CT) for cardiac sarcoidosis (CS) in patients with or without implantable devices, including a quantitative comparison with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). METHODS: Twenty-four patients (mean age, 64 ± 9 years; 17 women) with known or suspected CS underwent retrospective electrocardiogram-gated DE-CT at 80 kV with knowledge-based iterative model reconstruction. Fourteen patients without implantable devices also underwent LGE-CMR, while ten with pacemakers or implantable cardioverter-defibrillators did not. The presence of hyperenhanced myocardium was assessed visually and quantitatively using a 5-standard deviation threshold above the mean of remote myocardium. RESULTS: Inter-observer agreement for visual detection of hyperenhanced segments on DE-CT was excellent in patients with implantable devices and in those without (κ = 0.91 and κ = 0.94, respectively). Comparisons of the percent area of hyperenhanced myocardium between DE-CT and LGE-CMR on both per-patient and per-segment analyses showed good correlations (r = 0.96 and r = 0.83, respectively; p < 0.001). The sensitivity and specificity of DE-CT for the diagnosis of CS were 94% and 33%. CONCLUSIONS: The extent of hyperenhanced lesion with DE-CT showed good agreement with LGE-CMR results. DE-CT showed high sensitivity for detecting CS and may be useful particularly in patients with contraindications to CMR. KEY POINTS: • Delayed contrast-enhanced CT (DE-CT) can be applied to patients with implantable devices. • DE-CT can detect cardiac sarcoidosis (CS) lesions similarly to cardiac MRI. • DE-CT shows high sensitivity for detecting CS. • DE-CT may be useful particularly in patients with contraindications to cardiac MRI.

Bi-ventricular interplay in patients with systemic sclerosis-associated pulmonary arterial hypertension: Detection by cardiac magnetic resonance.

OBJECTIVES: Pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc) has a poor prognosis compared to PAH associated with other connective tissue diseases (CTD). The objective of this study was to examine the difference in hemodynamic state between SSc-PAH and other CTD-PAH by performing cardiac magnetic resonance (CMR) imaging. METHODS: A single center retrospective analysis was conducted comprising 40 consecutive CTD patients who underwent right heart catheterization and CMR at the same period from January 2010 to October 2015. RESULTS: Thirty-two patients had pre-capillary pulmonary hypertension. Of these, 15 had SSc and 17 had other CTD. CMR measurements, particularly the ratio of right to left end-diastolic volume (RVEDV/LVEDV), correlated well with mean pulmonary arterial pressure (mPAP). Conversely, RVEDV/LVEDV and mPAP correlated differently in SSc and non-SSc patients. In SSc patients, the ratio of RVEDV/LVEDV to mPAP was significantly higher compared to non-SSc patients. In the follow-up study, 2 SSc patients exhibited increased RVEDV/LVEDV in spite of decreased mPAP following treatment. Kaplan-Meier analysis revealed poor prognosis of patients with increased RVEDV/LVEDV following treatment. CONCLUSIONS: Our data indicated that altered bi-ventricular interplay detected at CMR may represent SSc-related cardiac involvement and reflect poor prognosis of SSc-PAH.

Comparison of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis.

PURPOSE: Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). (18)F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. METHODS: We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). RESULTS: Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). CONCLUSION: The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS.

The effects of 18-h fasting with low-carbohydrate diet preparation on suppressed physiological myocardial (18)F-fluorodeoxyglucose (FDG) uptake and possible minimal effects of unfractionated heparin use in patients with suspected cardiac involvement sarcoidosis.

BACKGROUND: (18)F-fluorodeoxyglucose (FDG) PET plays an important role in the detection of cardiac involvement sarcoidosis (CS). However, diffuse left ventricle (LV) wall uptake sometimes makes it difficult to distinguish between positive uptake and physiological uptake. The aims of this study were to evaluate the effects of 18-h fasting with low-carbohydrate diet (LCD) vs a minimum of 6-h fasting preparations on diffuse LV FDG uptake and free fatty acid (FFA) levels in patients with suspected CS. METHODS: Eighty-two patients with suspected CS were divided into 2 preparation protocols: one with a minimum 6-h fast without LCD preparation (group A, n = 58) and the other with a minimum 18-h fast with LCD preparation (group B, n = 24). All patients also received intravenous unfractionated heparin (UFH; 50 IU/kg) before the injection of FDG. RESULTS: Group A showed a higher percentage of diffuse LV uptake than did group B (27.6 vs 0.0%, P = .0041). Group B showed higher FFA levels (1159.1 ± 393.0, 650.5 ± 310.9 µEq/L, P < .0001) than did group A. Patients with diffuse LV uptake (n = 16) showed lower FFA levels than did other patients (n = 66) (432.1 ± 296.1, 888.4 ± 381.4 µEq/L, P < .0001). UFH administration significantly increased FFAs in both groups, even in the patients with diffuse LV FDG uptake. CONCLUSIONS: The 18-h fast with LCD preparation significantly reduced diffuse LV uptake and increased FFA levels. In particular, the FFA level was significantly lower in patients with LV diffuse uptake than in patients without LV diffuse uptake. Acutely increasing plasma FFA through the use of UFH may not have a significant role in reducing physiological LV FDG uptake.

FDG PET imaging for identifying pulmonary hypertension and right heart failure.

Pulmonary arterial hypertension (PAH) is a syndrome characterized by lung vascular intimal lesions, smooth muscle layer hypertrophy, perivascular inflammation, and concomitant right ventricular (RV) remodeling which can ultimately lead to the RV function decline known as RV failure (RVF). A key determining factor for RVF development is the RV metabolic state defined by the level of ischemia and glycolysis which constitute a vicious cycle of hypoxia, metabolic shift from glucose oxidation (GO) to glycolysis, increased RV systolic pressure (RVSP), decreased RV output, and further myocardial ischemia. In this context, 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) has been used for the measurement of glucose uptake (GU) as an indicator of glucose metabolism in the right heart and pulmonary vasculature. The focus of this review is the application of FDG PET modality for assessing PAH severity and clinical outcome.

Advanced imaging of cardiac sarcoidosis.

Sarcoidosis with cardiac involvement is underdiagnosed and can put patients at risk of morbidity including conduction defects, arrhythmias and heart failure, as well as sudden cardiac death. In addition, cardiac sarcoidosis may have no clinical manifestations or non-specific presentation and diagnosis may be difficult on clinical criteria. Investigation for cardiac sarcoidosis should be considered in those with extra-cardiac sarcoidosis and cardiac findings as well as those under the age of 60 years presenting with atrioventricular block without a clear cause. Advanced imaging modalities including cardiac magnetic resonance and positron emission tomography may help in both the diagnosis and assessment of response to treatment for cardiac sarcoidosis. This ultimately may help to minimize associated adverse outcomes from this enigmatic disease.

Atrioventricular block as the initial manifestation of cardiac sarcoidosis in middle-aged adults.

INTRODUCTION: Atrioventricular block (AVB) can be caused by several conditions, including cardiac sarcoidosis (CS). The prevalence of CS causing this presentation in a North American population has not been investigated and was the purpose of this study. METHODS: We prospectively evaluated patients aged 18-60 years presenting with unexplained 2nd or 3rd degree AVB and no previous history of sarcoidosis in any organ. All patients had fluorodeoxyglucose-positron emission tomography (FDG-PET) scans for the evaluation of CS. Japanese Ministry of Health Welfare (JMHW) criteria and biopsy results were used to confirm the diagnosis of CS. Subjects with advanced imaging suggestive of CS were investigated for extracardiac involvement. Patients were followed for major adverse cardiac events. RESULTS: Thirty-two patients presenting with unexplained AVB underwent cardiac and whole body FDG-PET for the investigation of CS from February 2010 to June 2013. Mean age was 52.8 ± 6.2 years, and 20 were male. CS was diagnosed in 11/32 (34%) subjects and 11/11 were subsequently diagnosed with extra-CS. Average follow-up was 21 ± 9 months. Adverse events were observed in 3 subjects with CS but none in subjects with idiopathic AVB. All 3 patients presented with heart failure, 2 also had recurrent VT resulting in ICD shocks. CONCLUSIONS: In this prospective study of consecutive patients aged ≤60 years presenting with unexplained AVB, we found that 11/32 (34%) had previously undiagnosed CS. Among patients with CS, 3/11 had adverse clinical outcomes compared with 0/21 (P = 0.011). Our data suggest that all patients aged ≤60 years with unexplained AVB should be investigated for CS. Moreover, patients diagnosed with CS should be closely followed.

Attenuated right ventricular energetics evaluated using ¹¹C-acetate PET in patients with pulmonary hypertension.

PURPOSE: The right ventricle (RV) has a high capacity to adapt to pressure or volume overload before failing. However, the mechanisms of RV adaptation, in particular RV energetics, in patients with pulmonary hypertension (PH) are still not well understood. We aimed to evaluate RV energetics including RV oxidative metabolism, power and efficiency to adapt to increasing pressure overload in patients with PH using (11)C-acetate PET. METHODS: In this prospective study, 27 patients with WHO functional class II/III PH (mean pulmonary arterial pressure 39.8 ± 13.5 mmHg) and 9 healthy individuals underwent (11)C-acetate PET. (11)C-acetate PET was used to simultaneously measure oxidative metabolism (k mono) for the left ventricle (LV) and RV. LV and RV efficiency were also calculated. RESULTS: The RV ejection fraction in PH patients was lower than in controls (p = 0.0054). There was no statistically significant difference in LV k mono (p = 0.09). In contrast, PH patients showed higher RV k mono than did controls (0.050 ± 0.009 min(-1) vs. 0.030 ± 0.006 min(-1), p < 0.0001). PH patients exhibited significantly increased RV power (p < 0.001) and hence increased RV efficiency compared to controls (0.40 ± 0.14 vs. 0.017 ± 0.12 mmHg·mL·min/g, p = 0.001). CONCLUSION: The RV oxidative metabolic rate was increased in patients with PH. Patients with WHO functional class II/III PH also had increased RV power and efficiency. These findings may indicate a myocardial energetics adaptation response to increasing pulmonary arterial pressure.