Hypertension and poor control of systolic blood pressure after a myocardial infarction with non-obstructive coronary arteries are associated with incident heart failure
Authors: Broo H , Yip Lundstrom L , Leosdottir M , Jernberg T , Tornvall P , Svensson P 
Published: November 2023

Abstract

Introduction
Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in up to 10% of all acute myocardial infarctions. Although previously believed to be a benign condition, recent studies have observed an increased risk for long-term adverse cardiovascular events in this group. However, data on risk markers for specific outcomes following MINOCA are limited. Hypertension is an important risk factor for heart failure (HF), but it is yet unknown whether blood pressure control after MINOCA is associated with incident HF.

Aims
To investigate whether history of hypertension and control of systolic blood pressure at two-month follow-up visit after MINOCA were associated with hospitalization for HF during long-term follow-up.

Material and Methods
This was a nationwide cohort study using data from SWEDEHEART and the National Patient Registry. Patients with first-time MINOCA between 2005-2020 were included and divided into grades of hypertension based on systolic blood pressure (SBP) in mmHg at a two-month follow-up visit. The grades were low normal (&lt;120), normal (120-129), high normal (130-139), grade 1 hypertension (140-159), grade 2 hypertension (160-179) and grade 3 hypertension (&gt;180). MINOCA was defined as a discharge diagnosis of AMI combined with a coronary angiography showing less than 50% stenosis in all coronary arteries. Patients with a diagnosis of heart failure or cardiomyopathy one month or earlier before index hospitalization with MINOCA were excluded. After the two-month visit all patients were followed in the registries regarding hospitalization for HF, until December 2020. The association between SBP and time to first HF hospitalization was studied with univariate and multivariate Cox regression models, using high normal SBP as the reference group.

Results
Among the 5018 included patients (57.8% women, mean age 62.6 years), 197 (3.9%) were hospitalized for HF during a median follow-up of 6.5 years (IQR 3.2-9.9). A diagnosis of hypertension at index hospitalization for MINOCA was associated with hospitalization for HF, both in univariate analysis (HR 1.97 95% CI 1.49-2.62) and after age and sex adjustments (HR 1.45 95% CI 1.09-1.93). The highest hospitalization rate of 7.6% was seen among patients with grade 2-3 hypertension at the two-month follow-up visit. In univariate analysis a SBP &gt;160 mmHg was associated with hospitalization for HF (HR 2.17 CI 1.36-3.45). After exclusion of patients with 30-49% stenosis, these findings remained after age and sex adjustments (HR 1.71 CI 1.04-2.83).

Conclusions
Both history of hypertension and a poor blood pressure control two-months after MINOCA were associated with hospitalization for HF during long-term follow-up. These findings highlight the importance of adequate blood pressure control following MINOCA. To better detect and treat high SBP should be seen as an opportunity to reduce HF hospitalizations in this group of patients.