First-pass perfusion cardiovascular magnetic resonance parameters as surrogate markers for left ventricular diastolic dysfunction: a validation against cardiac catheterization

Distribution of normalized pulmonary transit time per pathology in a population of routine CMR examinations

Pulmonary transit time (PTT), defined as the time taken for a contrast agent bolus to pass from the right ventricle to the left ventricle, is a surrogate for non-invasive assessment of preload. It is used in several imaging modalities: pulmonary angiography, echocardiography and cardiac magnetic resonance (CMR). Many recent studies have highlighted the prognostic value of PTT. Therefore, we sought to evaluate PTT in a consecutive cohort of patients undergoing CMR. We retrospectively evaluated PTT normalised for heart rate in 278 patients (66% male, mean age 58 ± 11 years) who underwent CMR between August 2017 and November 2021 with a diagnosis of dilated cardiomyopathy, infarct, hypertrophy, valvular, myocarditis, other pathology or no pathology ("normal"). Normalised pulmonary transit time (nPTT) was higher in men than in women (8.4 ± 1.3 beats vs 7.5 ± 1.1 beats, p = 0.002) in the "normal" group. nPTT was moderately correlated with left ventricular end-diastolic volume (LVEDV) (r2 = 0.19; p < 0.001), left ventricular end-systolic volume (LVESV) (r2 = 0.34; p < 0.001) and left ventricular ejection fraction (LVEF) (r2 = 0.29; p < 0.001). nPTT was significantly higher in patients with dilated cardiomyopathy (11.3 ± 5.4 beats; p < 0.001), infarct (9.5 ± 2.9 beats; p < 0.001) or valvular heart disease (9.5 ± 3.1 beats; p = 0.006) than in patients included in the "normal" group (7.9 ± 1.3 beats). The nPTT is an important marker of pathology. Its value depends on sex and type of pathology, but it is not specific for any type of pathology.

Pulmonary Transit Time Derived from First-Pass Perfusion Cardiac MR Imaging: A Potential New Marker for Cardiac Involvement and Prognosis in Light-Chain Amyloidosis

BACKGROUND

First-pass perfusion cardiac MR imaging could reflect pulmonary hemodynamics. However, the clinical value of pulmonary transit time (PTT) derived from first-pass perfusion MRI in light-chain (AL) amyloidosis requires further evaluation.

PURPOSE

To assess the clinical and prognostic value of PTT in patients with AL amyloidosis.

STUDY TYPE

Prospective observational study.

POPULATION

226 biopsy-proven systemic AL amyloidosis patients (age 58.62 ± 10.10 years, 135 males) and 43 healthy controls (age 42 ± 16.2 years, 20 males).

FIELD STRENGTH/SEQUENCE

SSFP cine and phase sensitive inversion recovery late gadolinium enhancement (LGE) sequences, and multislice first-pass myocardial perfusion imaging with a saturation recovery turbo fast low-angle shot (SR-TurboFLASH) pulse sequence at 3.0T.

ASSESSMENT

PTT was measured as the time interval between the peaks of right and left ventricular cavity arterial input function curves on first-pass perfusion MR images.

STATISTICAL TESTS

Independent-sample t test, Mann-Whitney U test, Chi-square test, Fisher's exact test, analysis of variance, or Kruskal-Wallis test, as appropriate; univariable and multivariable Cox proportional hazards models and Kaplan-Meier curves, area under receiver operating characteristic curve were used to determine statistical significance.

RESULTS

PTT could differentiate AL amyloidosis patients with (N = 188) and without (N = 38) cardiac involvement (area under the curve [AUC] = 0.839). During a median follow-up of 35 months, 160 patients (70.8%) demonstrated all-cause mortality. After adjustments for clinical (Hazard ratio [HR] 1.061, confidence interval [CI]: 1.021-1.102), biochemical (HR 1.055, CI: 1.014-1.097), cardiac MRI-derived (HR 1.077, CI: 1.034-1.123), and therapeutic (HR 1.063, CI: 1.024-1.103) factors, PTT predicted mortality independently in patients with AL amyloidosis. Finally, PTT could identify worse outcomes in patients demonstrating New York Heart Association class III, Mayo 2004 stage III, and transmural LGE pattern.

DATA CONCLUSION

PTT may serve as a new imaging predictor of cardiac involvement and prognosis in AL amyloidosis.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Association between systemic sclerosis and left ventricle dysfunction: Findings from observational studies

Objectives

Cardiac involvement is common in systemic sclerosis (SSc) patients. In this study, we aimed to systematically evaluate the relationship between SSc and left ventricular dysfunction (LVD), especially the left ventricular diastolic dysfunction, by ultrasound and cardiac magnetic resonance data.

Methods

We searched The Cochrane Library, PubMed and Embase databases collected studies about comparing LVD parameters in SSc patients and controls from establishment to January 2022. Furthermore, we also performed a two-sample MR using summary statistics from genome-wide association studies (GWAS) important LVD parameters, including left ventricular end-diastolic volume (LVEDV), left ventricular mass (LVM) and left ventricular ejection fraction (LVEF).

Results

Our meta-analysis included 31 eligible studies with 1448 SSc patients. According to the results, SSc patients had lower peak of early diastolic flow velocity/peak of late diastolic flow velocity ratio (E/A ratio), E, trans-mitral early filling peak velocity (E'), and left ventricular end-diastolic diameter (LVEDD) compared to controls. The E/E' ratio, A, left ventricular isovolumetric relaxation time (IVRT), deceleration Time (DT) and left atrial (LA) diameter were higher in SSc patients in comparison with controls. Moreover, we observed that the SSc patients had lower LVEF than controls. And in MR analysis, we also found that SSc was causally correlated with LVEF (OR = 0.9966, 95% CI 0.9935-0.998, P = 0.0398). However, unfortunately, there was no significant correlation between SSC and LVM (OR = 1.0048, 95% CI 0.9919-1.0179, P = 0.4661) and LVEDV (LVEDV OR = 0.9976, 95%CI 0.9888-1.0066, P = 0.6019).

Conclusion

SSc patients had diastolic/systolic dysfunction. However, MR analysis cannot confirm the genetic relationship between SSc and LVDD because of insufficient data. More research is needed to confirm the causal relationship between the two.