Angiographic microvascular resistance in patients with obstructive hypertrophic cardiomyopathy
1Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Insights
Coronary microvascular dysfunction in obstructive hypertrophic cardiomyopathy is assessed by angiographic microvascular resistance (AMR). High AMR predicts major adverse cardiovascular events, including heart failure, in oHCM patients.
Area of Science:
- Cardiology
- Vascular Medicine
- Cardiovascular Imaging
Background:
- Coronary microvascular dysfunction (CMD) is a key characteristic of obstructive hypertrophic cardiomyopathy (oHCM).
- Angiographic microvascular resistance (AMR) is a valuable method for assessing CMD.
Purpose of the Study:
- To investigate the prognostic significance of CMD burden, quantified by AMR, in patients with oHCM.
Main Methods:
- Retrospective analysis of 342 oHCM patients diagnosed between January 2017 and November 2021.
- Off-line AMR assessment for 3 major coronary vessels.
- Follow-up every 6 months to record major adverse cardiovascular events (MACE), including all-cause death and heart failure rehospitalization.
Main Results:
- High 3-vessel AMR (≥7.04) effectively predicted MACE (AUC: 0.70).
- Patients with high AMR (≥7.04) had significantly higher MACE rates (56.5% vs. 16.5%) compared to those with low AMR.
- High AMR was primarily driven by increased heart failure events; 3-vessel AMR and age were independent predictors of MACE.
Conclusions:
- Angiography-based AMR is a useful tool for evaluating CMD in oHCM patients.
- Elevated 3-vessel AMR (≥7.04) indicates a poorer prognosis in this population.
Background:
Coronary microvascular dysfunction (CMD) is an important feature of obstructive hypertrophic cardiomyopathy (oHCM). Angiographic microvascular resistance (AMR) offers a potent means for assessing CMD. This study sought to evaluate the prognostic value of CMD burden calculated by AMR among oHCM patients.
Methods:
We retrospectively screened all patients diagnosed with oHCM from Fuwai Hospital between January 2017 and November 2021. Off-line AMR assessments were performed for all 3 major coronary vessels by the independent imaging core laboratory. Patients were followed every 6 months post discharge via office visit or telephone contacts. The primary outcome was major adverse cardiovascular events (MACE), including all-cause death, and unplanned rehospitalization for heart failure.
Results:
A total of 342 patients presented with oHCM diseases enrolled in the present analyses. Mean age was 49.7, 57.6 % were men, mean 3-vessel AMR was 6.9. At a median follow-up of 18 months, high capability of 3-vessel AMR in predicting MACE was identified (AUC: 0.70) with the best cut-off value of 7.04. The primary endpoint of MACE was significantly higher in high microvascular resistance group (3-vessel AMR ≥ 7.04) as compared with low microvascular resistance group (56.5 % vs. 16.5 %; HR: 5.13; 95 % CI: 2.46-10.7; p < 0.001), which was mainly driven by the significantly higher risk of heart failure events in high microvascular resistance group. Additionally, 3-vessel AMR (HR: 4.37; 95 % CI: 1.99-9.58; p < 0.001), and age (per 1 year increase, HR: 1.03; 95 % CI: 1.01-1.06; p = 0.02) were independently associated with MACE.
Conclusion:
The present retrospective study demonstrated that the novel angiography-based AMR was a useful tool for CMD evaluation among patients with oHCM. High microvascular resistance as identified by 3-vessel AMR (≥7.04) was associated with worse prognosis.
