Ascending aortic blood pressure waveform is related to coronary atherosclerosis in hypertensive as well as in normotensive subjects

Bioengineered models of cardiovascular diseases

Age-associated cardiovascular diseases (CVDs), predominantly resulting from artery-related disorders such as atherosclerosis, stand as a leading cause of morbidity and mortality among the elderly population. Consequently, there is a growing interest in the development of clinically relevant bioengineered models of CVDs. Recent developments in bioengineering and material sciences have paved the way for the creation of intricate models that closely mimic the structure and surroundings of native cardiac tissues and blood vessels. These models can be utilized for basic research purposes and for identifying pharmaceutical interventions and facilitating drug discovery. The advancement of vessel-on-a-chip technologies and the development of bioengineered and humanized in vitro models of the cardiovascular system have the potential to revolutionize CVD disease modelling. These technologies offer pathophysiologically relevant models at a fraction of the cost and time required for traditional experimentation required in vivo. This progress signifies a significant advancement in the field, transitioning from conventional 2D cell culture models to advanced 3D organoid and vessel-on-a-chip models. These innovative models are specifically designed to explore the complexities of vascular aging and stiffening, crucial factors in the development of cardiovascular diseases. This review summarizes the recent progress of various bioengineered in vitro platforms developed for investigating the pathophysiology of human cardiovascular system with more focus on advanced 3D vascular platforms.

Vascular ageing: moving from bench towards bedside

Prevention of cardiovascular disease (CVD) remains one of the largest public health challenges of our time. Identifying individuals at increased cardiovascular risk at an asymptomatic, sub-clinical stage is of paramount importance for minimizing disease progression as well as the substantial health and economic burden associated with overt CVD. Vascular ageing (VA) involves the deterioration in vascular structure and function over time and ultimately leads to damage in the heart, brain, kidney, and other organs. Vascular ageing encompasses the cumulative effect of all cardiovascular risk factors on the arterial wall over the life course and thus may help identify those at elevated cardiovascular risk, early in disease development. Although the concept of VA is gaining interest clinically, it is seldom measured in routine clinical practice due to lack of consensus on how to characterize VA as physiological vs. pathological and various practical issues. In this state-of-the-art review and as a network of scientists, clinicians, engineers, and industry partners with expertise in VA, we address six questions related to VA in an attempt to increase knowledge among the broader medical community and move the routine measurement of VA a little closer from bench towards bedside.

Loss of hepatic PPARα in mice causes hypertension and cardiovascular disease

The leading cause of death in patients with nonalcoholic fatty liver disease (NAFLD) is cardiovascular disease (CVD). However, the mechanisms are unknown. Mice deficient in hepatocyte proliferator-activated receptor-α (PPARα) (PparaHepKO) exhibit hepatic steatosis on a regular chow diet, making them prone to manifesting NAFLD. We hypothesized that the PparaHepKO mice might be predisposed to poorer cardiovascular phenotypes due to increased liver fat content. Therefore, we used PparaHepKO and littermate control mice fed a regular chow diet to avoid complications with a high-fat diet, such as insulin resistance and increased adiposity. After 30 wk on a standard diet, male PparaHepKO mice exhibited elevated hepatic fat content compared with littermates as measured by Echo MRI (11.95 ± 1.4 vs. 3.74 ± 1.4%, P < 0.05), hepatic triglycerides (1.4 ± 0.10 vs. 0.3 ± 0.01 mM, P < 0.05), and Oil Red O staining, despite body weight, fasting blood glucose, and insulin levels being the same as controls. The PparaHepKO mice also displayed elevated mean arterial blood pressure (121 ± 4 vs. 108 ± 2 mmHg, P < 0.05), impaired diastolic function, cardiac remodeling, and enhanced vascular stiffness. To determine mechanisms controlling the increase in stiffness in the aorta, we used state-of-the-art PamGene technology to measure kinase activity in this tissue. Our data suggest that the loss of hepatic PPARα induces alterations in the aortas that reduce the kinase activity of tropomyosin receptor kinases and p70S6K kinase, which might contribute to the pathogenesis of NAFLD-induced CVD. These data indicate that hepatic PPARα protects the cardiovascular system through some as-of-yet undefined mechanism.

Association of Pulse Pressure With Clinical Outcomes in Patients Under Different Antiplatelet Strategies After Percutaneous Coronary Intervention: Analysis of GLOBAL LEADERS

BACKGROUND

We evaluated the association of pulse pressure (PP) and different antiplatelet regimes with clinical and safety outcomes in an all-comers percutaneous coronary intervention (PCI) population.

METHODS

In this analysis of GLOBAL LEADERS (n = 15,936) we compared the experimental therapy of 23 months of ticagrelor after 1 month of dual-antiplatelet therapy (DAPT) vs standard DAPT for 12 months followed by aspirin monotherapy in subjects who underwent PCI and were divided into 2 groups according to the median PP (60 mm Hg). The primary end point (all-cause death or new Q-wave myocardial infarction) and the composite end points: patient-oriented composite end points (POCE), Bleeding Academic Research Consortium (BARC) 3 or 5, and net adverse clinical events (NACE) were evaluated.

RESULTS

At 2 years, subjects in the high-PP group (n = 7971) had similar rates of the primary end point (4.3% vs 3.9%; P = 0.058), POCE (14.9% vs 12.7%; P = 0.051), and BARC 3 or 5 (2.5% vs 1.7%; P = 0.355) and higher rates of NACE (16.4% vs 13.7%; P = 0.037) compared with the low-PP group (n = 7965). Among patients with PP < 60 mm Hg, the primary end point (3.4% vs 4.4%, adjusted hazard ratio [aHR] 0.77, 95% confidence interval [CI] 0.61-0.96), POCE (11.8% vs 13.5%, aHR 0.86, 95% CI 0.76-0.98), NACE (12.8% vs 14.7%, aHR 0.85, 95% CI 0.76-0.96), and BARC 3 or 5 (1.4% vs 2.1%, aHR 0.69, 95% CI 0.49-0.97) were lower with ticagrelor monotherapy compared with DAPT. The only significant interaction was for BARC 3 or 5 (P = 0.008).

CONCLUSIONS

After contemporary PCI, subjects with high PP levels experienced high rates of NACE at 2 years. In those with low PP, ticagrelor monotherapy led to a lower risk of bleeding events compared with standard DAPT.

Assessment of the relationship between reperfusion success and T-peak to T-end interval in patients with ST elevation myocardial infarction treated with percutaneous coronary intervention

Objective:

T-peak–T-end (TPE) interval, which represents the dispersion of repolarization, is defined as the interval between the peak and end of the T-wave, and is associated with increased malignant ventricular arrhythmia and sudden cardiac death (SCD) in patients with ST elevation myocardial infarction (STEMI). Although prolonged TPE interval is associated with poor short- and long-term outcomes, even in patients with STEMI treated with successful primary percutaneous coronary intervention (pPCI), clinical, angiographic, and laboratory parameters that affect TPE remain to be elucidated. The aim of our study was to evaluate the potential relationship between prolonged TPE interval and reperfusion success using ST segment resolution (STR) in patients with STEMI undergoing pPCI.

Methods:

In the current study, 218 consecutive patients with STEMI who underwent pPCI were enrolled; after exclusion, 164 patients were included in the study population.

Results:

Patients were divided into two groups according to the presence of complete (STR%≥70) or incomplete (STR%<70) STR. Preprocedural corrected TPE (cTPE_PRE;116±21 ms vs. 108±21 ms; p=0.027), postprocedural TPE (TPE_POST; 107±16 ms vs. 92±21 ms; p<0.001), and postprocedural cTPE (cTPE_POST; 119±19 ms vs. 102±17 ms; p<0.001) intervals were significantly longer in patients with incomplete STR than in patients with complete STR, whereas there was no statistically significant difference between the two groups in terms of pre- and postprocedural and corrected QT intervals. cTPE_PRE and cTPE_POST were found to be independent predictors for incomplete STR.

Conclusion:

To our knowledge, this is the first study that evaluated the relationship between TPE interval and no-reflow defined by STR in patients with STEMI who were treated with pPCI.

Relationship between R-wave peak time and no-reflow in ST elevation myocardial infarction treated with a primary percutaneous coronary intervention

OBJECTIVES

Coronary no-reflow (NR) is observed in nearly half of ST segment elevation myocardial infarction (STEMI) patients who undergo a primary percutaneous coronary intervention (pPCI) despite epicardial coronary vessel patency. Several methods used to define NR include thrombolysis in myocardial infarction grade, corrected thrombolysis in myocardial infarction frame count, myocardial blush grade, ST-segment resolution, contrast echocardiography, and MRI. The aim of our study was to evaluate the relationship between NR and R-wave peak time (RWPT) measured from infarct-related artery leads METHOD: We enrolled 282 consecutive STEMI patients treated with pPCI in Kafkas University Hospital from January 2014 to January 2015. After exclusion, the remaining 233 patients were included in the study population RESULTS: Patients were divided into two groups according to the development of NR. We observed that increased preprocedural (31 (27-37) vs 27 (21-30) p<0,001) and postprocedural RWPT(35±7 vs 22±6 p<0,001) was associated with the development of NR and preprocedural RWPT(OR: 1.254 95% CI: 1.104-1.425 p<0,001) was found to be independent predictor of NR. The association between postprocedural RWPT and angiographic NR was statistically noninferior to that between ST-segment resolution % and NR(difference between area under curves: 0.0232, p= 0.38) CONCLUSION: the present study is the first to report a significant correlation between NR and RWPT in STEMI patients treated with primary pPCI.

An invasive but simple and accurate method for ascending aorta-femoral artery pulse wave velocity measurement

INTRODUCTION

Pulse wave velocity (PWV) is an emerging predictor in the assessment of cardiovascular risk in diseased and healthy populations. We suggest a novel method for the accurate measurement of PWV.

METHOD

PWV is calculated from pulse transit time using two separate pulse recordings over a known distance. 8F sheaths were placed in the right femoral arteries and routine coronary angiographies were performed with 5F diagnostic catheters. Ascending aorta pressures were measured with right diagnostic catheter tip in the ascending aorta and synchronous femoral artery pressures were measured with the sheath in the femoral artery. The distance between the two pressure sites was calculated as follows: total length of the right diagnostic catheter-length of the catheter outside the sheath-Sheath length.

RESULTS

We evaluated the PWV measured using the catheter method in 24 subjects. PWV correlated positively and independently with age (p = 0.004), coronary artery disease (p = 0.04), ascending aorta systolic pressure (p = 0.006), femoral artery systolic pressure (p = 0.008), ascending aorta pulse pressure (p = 0.003) and femoral artery pulse pressure (p = 0.04). In coronary artery disease patients, the mean PWV value was significantly higher than in patients with normal coronary arteries (12.61 ± 6.31 m/s vs 7.58 ± 2.26 m/s p = 0.04).

CONCLUSION

We describe a novel and accurate but invasive method for measurement of PWV. Our results may serve as a reference for non-invasive assessment of aorta-femoral artery PWV.

Impaired fibrillin-1 function promotes features of plaque instability in apolipoprotein E-deficient mice

BACKGROUND

Arterial stiffness has been associated with an increased cardiovascular risk. The aim of this study was to investigate the interaction between arterial stiffness and atherosclerosis.

METHODS AND RESULTS

Mice with a mutation C1039G+/-) in the fibrillin-1 gene leading to fragmentation of the elastic fibers were crossbred with apolipoprotein E-deficient (ApoE-/-) mice. Subsequently, ApoE-/- and ApoE-/-C1039G+/- mice were fed a Western-type diet for 10 or 20 weeks. Our results show that the interaction between arterial stiffness and atherosclerosis is bidirectional. On the one hand, arterial stiffness in ApoE-/-C1039G+/- mice increased more rapidly in the presence of atherosclerotic plaques. On the other hand, arterial stiffness promoted the development of larger and more unstable plaques in ApoE-/-C1039G+/- mice. The plaque area at the aortic root was increased 1.5- and 2.1-fold in ApoE-/-C1039G+/- mice after 10 and 20 weeks of Western-type diet, respectively. After 10 weeks of Western-type diet, plaques of ApoE-/-C1039G+/- mice showed increased apoptosis of smooth muscle cells, which was associated with a decrease in collagen content, an enlargement of the necrotic core, and an increase in macrophages. After 20 weeks of Western-type diet, the number of buried fibrous caps was increased in atherosclerotic lesions of ApoE-/-C1039G+/- mice, not only at the level of the aortic valves but also in the brachiocephalic artery and in the upper, middle, and lower thoracic aorta. Furthermore, acute plaque rupture was observed.

CONCLUSIONS

These results indicate that fragmentation of the elastic fibers leads to increased vascular stiffness, which promotes features of multifocal plaque instability.

Central blood pressure and hypertension: role in cardiovascular risk assessment

Although the differences between central and peripheral BP (blood pressure) have been known for decades, the consequences of decision-making based on peripheral rather than central BP have only recently been recognized. The influence of cyclic stretch (owing to cyclic changes in BP) on the aortic wall in atherosclerosis has been documented at every stage of its development. Apart from mediating atherosclerosis progression and plaque instability, the pulsatile component of BP is the main mechanism leading to plaque rupture and, consequently, to acute coronary syndromes and other vascular complications. The principal goal of the present review is to evaluate the role of central BP measurements, principally systolic and pulse pressure, for cardiovascular risk assessment. Recent findings suggest that the pulsatile component of BP (when represented by central pulse pressure or central pulsatility) is one of the most important factors determining event-free survival. Results of several prospective studies (using both invasive and non-invasive measurements of central BP) indicate not only an independent predictive value of central pulse pressure, but also its advantage over brachial pressure. Recent evidence suggests that some antihypertensive drugs can influence central BP more consistently when compared with peripheral BP. This is especially true for agents acting on the renin–angiotensin system. Nevertheless, large prospective studies aiming at the comparison of the predictive value of peripheral and central BP in the general population, as well as studies comparing the effectiveness of hypertension management based on peripheral compared with central BP measurements, are needed before algorithms based on central BP can be recommended for clinical practice.