Native T1 reference values for nonischemic cardiomyopathies and populations with increased cardiovascular risk: A systematic review and meta-analysis

Abstract

Background: Although cardiac MR and T₁ mapping are increasingly used to diagnose diffuse fibrosis based cardiac diseases, studies reporting T₁ values in healthy and diseased myocardium, particular in nonischemic cardiomyopathies (NICM) and populations with increased cardiovascular risk, seem contradictory.

Purpose: To determine the range of native myocardial T₁ value ranges in patients with NICM and populations with increased cardiovascular risk.

Study type: Systemic review and meta-analysis.

Population: Patients with NICM, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), and patients with myocarditis (MC), iron overload, amyloidosis, Fabry disease, and populations with hypertension (HT), diabetes mellitus (DM), and obesity. FIELD STRENGTH/SEQUENCE: (Shortened) modified Look-Locker inversion-recovery MR sequence at 1.5 or 3T.

Assessment: PubMed and Embase were searched following the PRISMA guidelines.

Statistical tests: The summary of standard mean difference (SMD) between the diseased and a healthy control populations was generated using a random-effects model in combination with meta-regression analysis.

Results: The SMD for HCM, DCM, and MC patients were significantly increased (1.41, 1.48, and 1.96, respectively, P < 0.01) compared with healthy controls. The SMD for HT patients with and without left-ventricle hypertrophy (LVH) together was significantly increased (0.19, P = 0.04), while for HT patients without LVH the SMD was zero (0.03, P = 0.52). The number of studies on amyloidosis, iron overload, Fabry disease, and HT patients with LVH did not meet the requirement to perform a meta-analysis. However, most studies reported a significantly increased T₁ for amyloidosis and HT patients with LVH and a significant decreased T₁ for iron overload and Fabry disease patients.

Data conclusions: Native T₁ mapping by using an (Sh)MOLLI sequence can potentially assess myocardial changes in HCM, DCM, MC, iron overload, amyloidosis, and Fabry disease compared to controls. In addition, it can help to diagnose left-ventricular remodeling in HT patients.

Level of evidence: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:891-912.

Keywords: (Sh)MOLLI; cardiac risk populations; diffuse fibrosis; meta-analysis; native T1 mapping; nonischemic cardiomyopathy.

Figure 1

Overview of study review process according to the PRISMA flow diagram.26

Figure 2

Weighted mean T₁ values with weighted mean and standard deviation of all included studies per HCM, DCM, MC, iron overload, amyloidosis, HT with (LVH+) and without (LVH–) left ventricular hypertrophy, DM, and OB population (black) and healthy controls (gray) in 1.5T studies.

Figure 3

Weighted mean T₁ values with weighted mean and standard deviation of all included studies per HCM, DCM, MC, iron overload, amyloidosis, HT with (LVH+) and without (LVH–) left ventricular hypertrophy, DM, and obesity population (black) and healthy controls (gray) in 3T studies.

Figure 4

Standardized mean difference between native myocardial T₁ of HCM patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 5

Standardized mean difference between native myocardial T₁ of DCM patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 6

Standardized mean difference between native myocardial T₁ of MC patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 7

Standardized mean difference between native myocardial T₁ of iron overload (IO) patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 8

Standardized mean difference between native myocardial T₁ of amyloidosis (AM) patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 9

Standardized mean difference between native myocardial T₁ of Fabry (FA) disease patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 10

Standardized mean difference between native myocardial T₁ of all HT patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance, F1 = female subgroup, M1 = male subgroup.

Figure 11

Standardized mean difference between native myocardial T₁ of HT patients without LVH with associated random effects weight factors, CI = confidence interval, IV = inverse variance, F1 = female subgroup, M1 = male subgroup.

Figure 12

Standardized mean difference between native myocardial T₁ of DM patients and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.

Figure 13

Standardized mean difference between native myocardial T₁ of obese (OB) populations and healthy controls with associated random effects weight factors, CI = confidence interval, IV = inverse variance.