Elevated myocardial wall stress after percutaneous coronary intervention in acute ST elevation myocardial infraction is associated with increased mortality

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Acute mechanical left ventricular (LV) support has been suggested to improve infarct tissue perfusion. However, its regulatory mechanism remains unclear. We investigated the physiological mechanisms in six Yorkshire pigs, which were subjected to 90-min balloon occlusion of the left anterior descending artery. During the acute reperfusion phase, LV support using an Impella heart pump was initiated. LV pressure, coronary flow and pressure of the infarct artery were simultaneously recorded to evaluate the impact of LV support on coronary physiology. Coronary wave intensity was calculated to understand the forces regulating coronary flow. Significant increases in coronary flow velocity and its area under the curve were found after mechanical LV support. Among the coronary flow-regulating factors, coronary pressure was increased mainly during the late diastolic phase with less pulsatility. Meanwhile, LV pressure was reduced throughout diastole resulting in significant and consistent elevation of coronary driving pressure. Interestingly, the duration of diastole was prolonged with LV support. In the wave intensity analysis, the duration between backward suction and pushing waves was extended, indicating that earlier myocardial relaxation and delayed contraction contributed to the extension of diastole. In conclusion, mechanical LV support increases infarct coronary flow by extending diastole and augmenting coronary driving pressure. These changes were mainly driven by reduced LV diastolic pressure, indicating that the key regulator of coronary flow under mechanical LV support is downstream of the coronary artery, rather than upstream. Our study highlights the importance of LV diastolic pressure in infarct coronary flow regulation. KEY POINTS: Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Although mechanical left ventricular (LV) support has been suggested to improve infarct coronary flow, its specific mechanism remains to be clarified. LV support reduced LV pressure, and elevated coronary pressure during the late diastolic phase, resulting in high coronary driving pressure. This study demonstrated for the first time that mechanical LV support extends diastolic phase, leading to increased infarct coronary flow. Future studies should evaluate the correlation between improved infarct coronary flow and resulting infarct size.

Central stress pathways in the development of cardiovascular disease

PURPOSE

Mental stress is of essential consideration when assessing cardiovascular pathophysiology in all patient populations. Substantial evidence indicates associations among stress, cardiovascular disease and aberrant brain-body communication. However, our understanding of the flow of stress information in humans, is limited, despite the crucial insights this area may offer into future therapeutic targets for clinical intervention.

METHODS

Key terms including mental stress, cardiovascular disease and central control, were searched in PubMed, ScienceDirect and Scopus databases. Articles indicative of heart rate and blood pressure regulation, or central control of cardiovascular disease through direct neural innervation of the cardiac, splanchnic and vascular regions were included. Focus on human neuroimaging research and the flow of stress information is described, before brain-body connectivity, via pre-motor brainstem intermediates is discussed. Lastly, we review current understandings of pathophysiological stress and cardiovascular disease aetiology.

RESULTS

Structural and functional changes to corticolimbic circuitry encode stress information, integrated by the hypothalamus and amygdala. Pre-autonomic brain-body relays to brainstem and spinal cord nuclei establish dysautonomia and lead to alterations in baroreflex functioning, firing of the sympathetic fibres, cellular reuptake of norepinephrine and withdrawal of the parasympathetic reflex. The combined result is profoundly adrenergic and increases the likelihood of cardiac myopathy, arrhythmogenesis, coronary ischaemia, hypertension and the overall risk of future sudden stress-induced heart failure.

CONCLUSIONS

There is undeniable support that mental stress contributes to the development of cardiovascular disease. The emerging accumulation of large-scale multimodal neuroimaging data analytics to assess this relationship promises exciting novel therapeutic targets for future cardiovascular disease detection and prevention.

Berengy M, Abozid E, Reihan MS. Heart Failure and Echocardiography Derived Myocardial Wall Stress Link in Diabetic Cases with Acute Myocardial Infarction Managed by Revascularization

Background

Diabetes is associated with left ventricular remodeling. Myocardial wall stress is a measurable factor connected to the ventricular breadth and force and is related to myocardial thickness; it can be measured by echocardiography. The present study aimed to assess the link between heart failure (HF) and echocardiography-derived myocardial wall stress in diabetic patients with ST elevation myocardial infarction (STEMI) who were managed with revascularization.

Methods

This study was a comparative prospective study that took place between February 2022 and February 2023. It included 100 diabetic patients presented with STEMI and managed by percutaneous coronary intervention (PCI). Patients were selected from the cardiology departments at Al-Azhar University Hospital, Damietta, Egypt. During the hospital stay, patients were checked for HF symptoms and signs. They were also observed for 3 months after discharge for detection of HF. Those who did not develop HF were assigned to group I, and those with HF were assigned to group II.

Results

The mean value of end-systolic wall stress (ESWS) was 77.09 ± 12.22 and 97 ± 13.44, and the mean value of end-diastolic wall stress (EDWS) was 12.61 ± 2.76 and 15.87 ± 2.86 in groups I and II respectively, with significant differences between the 2 groups. The cutoff point to detect HF was 88 KPa for ESWS and 13.5 KPa for EDWS, with a sensitivity of 70% and 79% and a specificity of 80% and 61% for ESWS and EDWS, respectively.

Conclusion

Elevated left ventricle (LV) myocardial stress is related to increased HF in diabetic patients whose HF was managed by PCI after STEMI. LV wall stress is a potentially helpful risk stratification tool using routine echocardiography to determine the treatment plane according to the risk status.

SRPX2 attenuated oxygen–glucose deprivation and reperfusion-induced injury in cardiomyocytes via alleviating endoplasmic reticulum stress-induced apoptosis through targeting PI3K/Akt/mTOR axis

Myocardial infraction (MI) is the leading cause of high morbidity and mortality worldwide. It was still urgently needed to find new and effective drugs for MI treatment by the use of myocardial ischemia/reperfusion (I/R) model. Sushi repeats contain the protein X-Linked 2 (SRPX2), which regulates a variety of important cell functions. However, its possible role in myocardial I/R and the progression of MI is still unclear. In this study, we investigated the role of SRPX2 in myocardial I/R. SRPX2 showed low expression in IR rats and H9C2 cells induced by oxygen–glucose deprivation/reperfusion (OGD/R). SRPX2 could increase OGD/R-induced H9C2 cell survival. In addition, SRPX2 suppressed the apoptosis of OGD/R-induced H9C2 cells. Furthermore, we found that SRPX2 could inhibit ER stress induced by OGD/R in H9C2 cells. Mechanically, we found that SRPX2 suppressed the PI3K/Akt/mTOR pathway, thus attenuating OGD/R -induced injury in H9C2 cells. Therefore, SRPX2 has the potential to serve as a target for MI treatment.