Myosin Heavy-Chain-Associated RNA Transcript for Cardiopulmonary Recovery Prediction in High-Intensity Interval Training for Coronary Artery Disease

Summary

Serum myosin heavy-chain-associated RNA transcript (MHRT) levels were elevated in patients with coronary artery disease (CAD) but decreased after high-intensity interval training (HIIT). HIIT improved cardiopulmonary function and quality of life, while MHRT showed potential as a biomarker for monitoring HIIT response and treatment efficacy in CAD.

Abstract

This study highlights the expression characteristics of MHRT in CAD and analyzes its predictive potential regarding HIIT intervention on cardiopulmonary function and quality of life in CAD patients. A total of 88 CAD patients were enrolled, and non-CAD volunteers were randomly recruited as the study sample. Serum levels of MHRT were assessed by qRT-PCR. The association between MHRT levels and the Gensini score was assessed using Pearson's correlation analysis. The predictive value of MHRT in CAD was evaluated using ROC curves and logistic regression. Serum MHRT expression was elevated in CAD and correlated positively with the Gensini score. Cardiopulmonary function indicators and quality-of-life scores increased after the HIIT intervention in the HIIT group. Furthermore, serum MHRT decreased after the HIIT intervention, and levels were lower in the clinically effective group than in the ineffective group. HIIT significantly improved cardiopulmonary function and quality of life in CAD patients, accompanied by a marked reduction in serum MHRT levels. This suggests that MHRT may serve as a potential biomarker for monitoring HIIT efficacy.

Introduction

Coronary artery disease (CAD) is a general term for cardiovascular diseases characterized by myocardial ischemia, hypoxia, or necrosis caused by the narrowing or blockage of the coronary arteries^1,2. Clinically, coronary heart disease is the most common form of CAD, involving complex interactions between genetic susceptibility and modifiable lifestyle factors, many of which are not entirely preventable³. Consequently, current therapeutic approaches primarily focus on disease management rather than complete cure. The accelerating demographic aging in China has contributed to a rising prevalence of cardiovascular disorders, particularly CAD, posing escalating threats to patient mortality and overall public health security⁴. Exercise-based rehabilitation is a crucial component of post-operative management for CAD patients, demonstrating significant potential to enhance cardiopulmonary functional recovery⁵. High-intensity interval training (HIIT) is a training method that combines high-intensity exercise and short rest⁶. In past clinical practice, HIIT was considered useful for exercise and recovery in patients with cardiovascular disease^7,8. Consequently, this investigation was designed to evaluate the therapeutic potential of HIIT to enhance post-operative recovery outcomes in CAD patients.

Long non-coding RNAs (lncRNAs) can mediate gene expression regulation, although they have no capacity for direct protein coding⁹. The significant variations in lncRNAs in different diseases and their stable structures make them valuable for reliable applications in disease prediction and treatment. In the context of CAD, lncRNAs ANRIL, PVT1, and UCA1 have been reported to intervene in the development of the disease^10,11,12. LncRNA MHRT (myosin heavy chain-associated RNA transcript) is mostly present in myocardial tissue¹³. A study showed that MHRT was prominently expressed in the heart¹⁴. There is also evidence that MHRT can promote the activity of cardiomyocytes and reduce apoptosis, and overexpression of MHRT may be a diagnostic marker for acute myocardial infarction¹⁵. More critically, MHRT was implicated as a critical modulator in both diagnostic stratification and prognostic evaluation of coronary artery disease¹⁶. Therefore, it is hypothesized that MHRT is also expressed in CAD and may contribute to disease progression.

This study quantitatively analyzed serum MHRT levels in CAD patients, primarily evaluating the regulatory effect of HIIT intervention on MHRT levels and its association with physical rehabilitation. Additionally, it elucidated the effects of HIIT on cardiopulmonary function and quality of life in CAD patients, while investigating the clinical value of MHRT as a potential biomarker to assess HIIT rehabilitation efficacy.

Protocol

A total of 88 patients with CAD admitted to Wuhan Xinzhou District People′s Hospital from March 2023 to May 2024 were selected (CAD group), and 88 volunteers who underwent coronary angiography and were judged to be free of CAD were also recruited (non-CAD group). Inclusion criteria: Adherence to the criteria described in the Guidelines for the diagnosis and Treatment of CAD¹⁷. No other blood system diseases or immune system diseases. Normal cognitive function without a history of psychiatric disorders. No history of cardiovascular disease. Exclusion criteria: Comorbidity with oncological diseases or other chronic diseases. Comorbidity with severe infectious diseases. Severe heart failure. Withdrawal from follow-up midway. The experimental protocol received ethical approval from the Wuhan Xinzhou District People′s Hospital Institutional Review Board (No. 2023A03), and written informed consent was obtained from all study participants prior to enrollment. All the materials used in this study are listed in the Table of Materials.

Nursing intervention and efficacy grouping

Patients with CAD who underwent percutaneous coronary intervention (PCI) were recruited, and using a random-number table, patients were randomly assigned in a 1:1 ratio to either the HIIT group (n = 44) or the usual care group (non-HIIT, n = 44). To ensure concealment of assignments, the randomization sequence was generated by an independent investigator and placed in sequentially numbered, opaque envelopes. Blinding of subjects and intervention implementors was not possible due to the nature of the exercise intervention, but outcome assessment and data analysis personnel were always blinded. Patients in the non-HIIT group received moderate-intensity exercise training for 1 week after surgery at 60% to 80% of maximal heart rate, as determined by wristband monitoring, for 28 min per session. The training frequency was three times per week, and the patients were free to choose their preferred exercise methods, such as jogging and aerobic exercise. Furthermore, patients in the HIIT group underwent HIIT one week after surgery while receiving postoperative care. Briefly, train at 85% to 95% of maximum heart rate for 4 min, followed by 40% of maximum heart rate for 3 min. A total of 4 groups were performed, which took 28 min at a frequency of 3 times/week¹⁸. The patients were examined before training and monitored throughout the one-month training period. The endpoint was defined as an inability to complete the training program due to worsening disease or poor adherence. Calculated the change in 6MWT distance before and after intervention in CAD patients within the HIIT group. Using the median as the cutoff, patients with values above this threshold were defined as the effective group, and the remainder as the ineffective group.

Collection of clinical indicators

Venous blood was collected from participants before, during, and after the HIIT intervention, centrifuged for 15 min (2500 × g), and separated to obtain the upper serum layer, which was stored at -80 °C for examination. The biochemical indices were tested by an automatic blood analyzer. The degree of coronary artery disease in patients was assessed using the Gensini score, with higher scores indicating more severe coronary artery disease¹⁹. A pulmonary function instrument and a cardiovascular ultrasound system were selected to monitor cardiopulmonary function. Patients' quality of life is measured according to the World Health Organization Quality of Life Instrument-BREF (WHOQOL-BREF), which includes social relationships, environment, physical health, and psychological health²⁰. Scores on each domain range from 0 to 30, with higher scores indicating better quality of life.

qRT-PCR

RNA in serum samples was extracted. The cDNA samples were prepared using the reverse transcription Kit. PCR mixtures were prepared using the SYBR Premix Ex Taq Kit, and quantitative reactions were performed on Real-Time PCR system. MHRT expression was normalized by GAPDH and calculated by the 2^-ΔΔCt method.

Statistical methods

SPSS 26 and GraphPad Prism 9 were used to analyze and process all data. The Shapiro-Wilk test was used to assess the normality of the data distribution. Measurement information was expressed as mean ± standard deviation, count information was expressed as n/%, and comparisons between groups were made by t-test or chi-square test. For multiple comparisons, error was controlled with the use of the Bonferroni correction. The predictive value of MHRT was evaluated using the ROC method. Risk factors for CAD were assessed using Pearson's correlation and logistic regression. p < 0.05 was considered statistically significant.

Results

Assessment of clinical features

The baseline characteristics of the enrolled subjects are shown in Table 1. In the CAD group, hsCRP was elevated (p < 0.001), except for a decrease in HDL-C levels (p = 0.003), compared with the non-CAD group. LDL-C, TC, and TG levels, as well as general indicators (p > 0.05), were not statistically different between the two groups.

MHRT expression was upregula...

Discussion

Coronary heart disease (CAD), a prevalent cardiovascular disorder characterized by impaired myocardial perfusion, has witnessed a significant rise in prevalence attributed to modern lifestyle alterations²¹. This condition is associated with unfavorable clinical outcomes, substantially compromising both quality of life and long-term survival. Exercise rehabilitation training is a rehabilitation method of clinical concern at present, and some studies have claimed that patients with CAD can effective...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
ABI 7500 Real-Time PCR system	Applied Biosystems, USA	4368814	qRT-PCR
Automatic blood analyzer	Hitachi 7180, Japan	7180	Biochemical indexes
Cardiovascular ultrasound system	PHILIP, Netherlands	CX50	Cardiac function
Centrifuge	Thermo Scientific, USA	75002446	Sample processing
GraphPad Prism 9	GraphPad software	9.0	Data analysis
Pulmonary function instrument	CONTEC, China	SP10	Cardiopulmonary function
QuantiTect Reverse Transcription Kit	Qiagen, USA	205311	cDNA synthesis
Refrigerator	Haier, Qingdao, China	DW-86L828J	Sample preservation
SPSS 26	SPSS software	26.0	Data analysis
SYBR Premix Ex Taq Kit	Takara, China	RR420A	PCR mixture
TRIzol reagent	Invitrogen, USA	15596026	RNA extraction