Extracellular volume quantification in isolated hypertension - changes at the detectable limits?

Abstract

BackgroundDiffuse myocardial fibrosis (DMF) is important in cardiovascular disease, however until recently could only be assessed by invasive biopsy. We hypothesised that DMF measured by T1 mapping is elevated in isolated systemic hypertension.MethodsIn a study of well-controlled hypertensive patients from a specialist tertiary centre, 46 hypertensive patients (median age 56, range 21 to 78, 52 % male) and 50 healthy volunteers (median age 45, range 28 to 69, 52 % male) underwent clinical CMR at 1.5 T with T1 mapping (ShMOLLI) using the equilibrium contrast technique for extracellular volume (ECV) quantification. Patients underwent 24-hours Automated Blood Pressure Monitoring (ABPM), echocardiographic assessment of diastolic function, aortic stiffness assessment and measurement of NT-pro-BNP and collagen biomarkers.ResultsLate gadolinium enhancement (LGE) revealed significant unexpected underlying pathology in 6 out of 46 patients (13 %; myocardial infarction n = 3; hypertrophic cardiomyopathy (HCM) n = 3); these were subsequently excluded. Limited, non-ischaemic LGE patterns were seen in 11 out of the remaining 40 (28 %) patients. Hypertensives on therapy (mean 2.2 agents) had a mean ABPM of 152/88 mmHg, but only 35 % (14/40) had left ventricular hypertrophy (LVH; LV mass male > 90 g/m2; female > 78 g/m2). Native myocardial T1 was similar in hypertensives and controls (955 ± 30 ms versus 965 ± 38 ms, p = 0.16). The difference in ECV did not reach significance (0.26 ± 0.02 versus 0.27 ± 0.03, p = 0.06). In the subset with LVH, the ECV was significantly higher (0.28 ± 0.03 versus 0.26 ± 0.02, p < 0.001).ConclusionIn well-controlled hypertensive patients, conventional CMR discovered significant underlying diseases (chronic infarction, HCM) not detected by echocardiography previously or even during this study. T1 mapping revealed increased diffuse myocardial fibrosis, but the increases were small and only occurred with LVH.

Mechanisms for the Formation Myocardial Fibrosis in Norm and in Certain Cardiovascular Diseases, How to Diagnose It

“…Этот метод является наиболее пригод-ным для выявления инфаркта миокарда, где различия между нормальным и пострадавшим миокардом более отчетливы. Определение внеклеточного объема может обнаружить ранние изменения, связанные с фиброзом, которые не всегда обнаруживают при исследовании с замедленным выведением гадолиния [19][20][21].…”

Antecedent Hypertension and Myocardial Injury in Patients With Reperfused St-Elevation Myocardial Infarction

“…Since both have been proved to be associated with adverse clinical outcome in STEMI patients [27], these factors might also contribute to the increased risk of infarction patients with antecedent HTN. Recent studies could also disclose that diffuse myocardial fibrosis, measured by T1 mapping, is increased in patients with hypertension and previous infarction [28].…”

Asymptomatic Cocaine Abuse ― Myocardial Tissue Characterization Using Cardiac Biomarkers and Cardiovascular Magnetic Resonance Imaging ―

“…Nevertheless, we cannot exclude early, diffuse myocardial tissue alterations under the detectable limits, similar to other recent findings in patients with arterial hypertension. 46 assessment in 20 asymptomatic, long-term CA involving resting ECG, exercise ECG, circulating biomarkers, echocardiography and advanced CMR techniques such as ECV imaging to detect diffuse myocardial injury. We found that asymptomatic CA had normal LV volumes, mass and function as well as normal circulating biomarkers compared with healthy volunteers.…”