• First-of-its-kind study by NHCS researchers shows adverse association between heart muscle scarring (also known as myocardial fibrosis) and patients with hypertension, detected non-invasively using cardiac magnetic resonance imaging (CMR). 
• This group of patients could be risk-stratified using CMR and intervened early with targeted medications.
• 
  NHCS has embarked on an ongoing trial to examine the potential of targeted medications to reverse heart muscle scarring and avert worse cardiovascular outcome.

In Singapore, the prevalence of hypertension has shown an increase from 24.2% in 2017 to  35.5% in 2019 to 20201 and it is a major cause of ischemic heart disease, strokes and heart  failure2,3,4. Although conventional medical treatment is able to control one’s blood pressure, it does not completely ameliorate or eliminate risks of cardiovascular disease. For instance,  about 30% of these cardiovascular events occur in patients with well-controlled blood  pressure4. 

In this prospective and observational study, titled REMODEL (Response of the Myocardium  to Hypertrophic Conditions in the Adult Population)5led by Associate Professor Calvin Chin,  Clinician Scientist and Senior Consultant from the Department of Cardiology at NHCS, CMR was performed in close to 800 patients with hypertension. The patients were followed up for  adverse cardiovascular events over an average period of more than three years. CMR is a  useful diagnostic tool which detects heart structural abnormalities and quantifies fibrosis  without the invasive sampling of heart muscle tissues. 

Myocardial fibrosis typically happens in patients with previous heart attacks. Correspondingly,  patients in the REMODEL study did not have previous heart attacks, hence any occurrence of  myocardial fibrosis have been deduced to that of patient’s susceptibility to blood pressure, and  other reasons such as genetic predisposition and other medical co-morbidities like diabetes.  

“Although anecdotal reports have previously shown the presence of heart muscle scarring in  patients with hypertension, this is the first study that confirms the adverse association between  scarring of heart muscle and the cardiovascular outcomes in patients with hypertension. We  found that heart muscle scarring is a stronger predictor of adverse outcomes even after  correcting for patients’ age, sex and systolic blood pressures,” said Assoc Prof Calvin Chin,  who is also the Director of Cardiac Magnetic Resonance Imaging at NHCS.  

The research team further found that the heart muscle response to hypertension in patients is heterogeneous or diverse, whereby while two patients may have similar blood pressure, their  myocardial characteristics can be different. This presents opportunities to tailor and  personalise treatment for hypertensive patients who have heart muscle scarring to reduce  potential risk of future cardiovascular events, beyond lowering their blood pressure and  achieving their blood pressure targets. 

Following these findings that were published this year in the medical Journal Hypertension,  Assoc Prof Calvin Chin and the team are now into the next phase of an ongoing trial  REVERSE-LVH6to assess the potential of reversing heart muscle scarring, through the use  of specific therapies targeted at fibrosis in patients with hypertensive heart disease.  REVERSE-LVH is a randomised controlled study to compare the efficacy of medications in  regressing myocardial fibrosis. Patients recruited in the study would undergo CMR after a year  to quantity the amount of myocardial fibrosis detected before and after treatment.  

“Using CMR, a non-invasive tool to detect fibrosis has potential to improve risk-stratification of  patients with hypertension. Targeted anti-fibrotic intervention, if proven effective, could have  direct impact on clinical practice and help selected patients with hypertension lead better  quality of life and have better health outcomes,” said Assoc Prof Calvin Chin. 

References: 

1. Key Highlights from the National Population Health Survey 2020. https://www.singstat.gov.sg.  2. Drazner MH. The Progression of Hypertensive Heart Disease. Circulation. 2011;123(3):327-334.  3. Messerli FH, Rimoldi SF, Bangalore S. The Transition from Hypertension to Heart Failure:  Contemporary Update. JACC: Heart Failure.  
2. Forouzanfar MH, Liu P, Roth GA, et al. Global Burden of Hypertension and Systolic Blood Pressure  of at Least 110 to 115 mm Hg, 1990-2015. JAMA. 2017;317(2):165-18. 
3. Iyer NR, Le TT, Kui MSL, Tang HC, Chin CT, Phua SK, Bryant JA, Pua CJ, Ang B, Toh DF, Aw TC,  Lee CH, Cook SA, Ugander M, Chin CWL. Markers of Focal and Diffuse Nonischemic Myocardial  Fibrosis Are Associated With Adverse Cardiac Remodeling and Prognosis in Patients With  Hypertension: The REMODEL Study. Hypertension. 2022 May  23:101161HYPERTENSIONAHA12219225. doi: 10.1161/HYPERTENSIONAHA.122.19225. Epub  ahead of print. PMID: 35603595. 
4. REVERSE-LVH. https://clinicaltrials.gov/ct2/show/NCT03553810