Do treatment-induced changes in arterial stiffness affect left ventricular structure? A meta-analysis

Hypertension mediated kidney and cardiovascular damage and risk stratification: Redefining concepts

Hypertension mediated organ damage (HMOD) refers to structural or functional changes in arteries or target organs that can be present in long-standing hypertension, but it can be also found in naïve never treated patients. Traditionally, cardiovascular risk is stratified with charts or calculators that tend to underestimate the real cardiovascular risk. The diagnosis of HMOD automatically reclassifies patients to the highest level of cardiovascular risk. Subclinical HMOD can be present already at the diagnosis of hypertension and more than 25% of hypertensives are misclassified with the routine tests recommended by hypertension guidelines. Whether HMOD regression improves cardiovascular outcomes has never been investigated in randomized clinical trials and remains controversial. However, different drugs have been probed with promising results in high cardiovascular risk patients, such as the new antidiabetic or the novel non-steroid mineralocorticoid antagonists. Accordingly, trials have shown that lowering blood pressure reduces cardiovascular events. In this narrative review, we will discuss the role of HMOD in cardiovascular risk stratification, the different types of organ damage, and the evidence available to define whether HMOD can be used as a therapeutic target.

Impact of Hypertension History and Blood Pressure at Presentation on Cardiac Remodeling and Mortality in Aortic Dissection

Objective

This study compared clinical, echocardiographic, and prognostic characteristics among patients with aortic dissection (AD) with (HypHist) and without (No-HypHist) hypertension history and evaluated the association of blood pressure (BP) at presentation with 1-year mortality, left ventricular (LV) remodeling and renal dysfunction.

Methods

We investigated clinical and echocardiographic characteristics and 1-year mortality among 367 patients with AD (81% HypHist, 66% Type-A) from three Brazilian centers.

Results

Patients with No-HypHist were more likely to have Marfan syndrome, bicuspid aortic valve, to undergo surgical therapy, were less likely to have LV hypertrophy and concentricity, and had similar mortality compared with HypHist patients. Adjusted restricted cubic spline analysis showed that systolic BP (SBP) and diastolic BP (DBP) at presentation had a J-curve association with mortality among patients with No-HypHist, but did not associate with death among patients with HypHist (p for interaction = 0.001 for SBP and = 0.022 for DBP). Conversely, the association between SBP at presentation and mortality was influenced by previous use of antihypertensive medications in the HypHist group (p for interaction = 0.002). Results of multivariable logistic regression analysis comprising the whole sample showed direct associations of SBP and DBP at presentation with LV hypertrophy (p = 0.009) and LV concentricity (p = 0.015), respectively, and an inverse association between pulse pressure at presentation and estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² (p = 0.008).

Conclusion

Combined information on BP at presentation, previous diagnosis of hypertension, and use of antihypertensive medications might be useful to predict mortality risk and to estimate extra-aortic end-organ damage among patients with AD.

Microcirculation and Macrocirculation in Hypertension: A Dangerous Cross-Link?

Microcirculation and macrocirculation are tightly interconnected into a dangerous cross-link in hypertension. Small artery damage includes functional (vasoconstriction, impaired vasodilatation) and structural abnormalities (mostly inward eutrophic remodeling). These abnormalities are major determinants of the increase in total peripheral resistance and mean blood pressure (BP) in primary hypertension, which in the long term induces large artery stiffening. In turn, large artery stiffening increases central systolic and pulse pressures, which are further augmented by wave reflection in response to the structural alterations in small resistance arteries. Finally, transmission of high BP and flow pulsatility to small resistance arteries further induces functional and structural abnormalities, thus leading to increased total peripheral resistance and mean BP, thus perpetuating the vicious circle. Hyperpulsatility, in addition to higher mean BP, exaggerates cardiac, brain, and kidney damages and leads to cardiovascular, cerebral, and renal complications. The dangerous cross-link between micro and macrocirculation can be reversed into a virtuous one by ACE (angiotensin-converting enzyme) inhibitors, sartans, and calcium channel blockers. These three pharmacological classes are more potent than β-blockers and diuretics for reducing arterial stiffness and small artery remodeling. The same ranking was observed for their effectiveness at reducing left ventricular hypertrophy, preserving glomerular filtration rate, and preventing dementia, suggesting that they can act beyond brachial BP reduction, by breaking the micro/macrocirculation vicious circle.

SPARTE Study: Normalization of Arterial Stiffness and Cardiovascular Events in Patients With Hypertension at Medium to Very High Risk

Supplemental Digital Content is available in the text.

The SPARTE study (Strategy for Preventing cardiovascular and renal events based on ARTErial stiffness; URL: https://www.clinicaltrials.gov; Unique identifier: NCT02617238) is a multicenter open-label randomized controlled trial with blinded end point evaluation, undertaken at 25 French research centers in university hospitals. Patients with primary hypertension were randomly assigned (1:1) to a therapeutic strategy targeting the normalization of carotid-femoral pulse wave velocity (PWV) measured every 6 months (PWV group, n=264) versus a classical therapeutic strategy only implementing the European Guidelines for Hypertension Treatment (conventional group, n=272). In the PWV group, the therapeutic strategy used preferably a combination of ACE (angiotensin-converting enzyme) inhibitor or angiotensin receptor blocker and calcium channel blockers, as well as maximal recommended doses of ACE inhibitors and angiotensin receptor blockers. The primary outcome was a combined end point including particularly stroke and coronary events. Secondary outcomes included the time-course changes in brachial office blood pressure (BP), ambulatory BP, PWV, and treatments. After a median follow-up of 48.3 months, there was no significant between-group difference in primary outcome (hazard ratio, 0.74 [95% CI, 0.40–1.38], P=0.35). In the PWV group, combinations of renin-angiotensin-system blockers and calcium channel blockers were prescribed at higher dosage (P=0.028), office and ambulatory systolic blood pressure and diastolic blood pressure decreased more (P<0.001 and P<0.01, respectively), and PWV increased less (P=0.0003) than in the conventional group. The SPARTE study lacked sufficient statistical power to demonstrate its primary outcome. However, it demonstrated that a PWV-driven treatment for hypertension enables to further reduce office and ambulatory systolic blood pressure and diastolic blood pressure and prevent vascular aging in patients with hypertension at medium-to-very-high risk, compared with strict application of guidelines.

The Putative Role of Methylglyoxal in Arterial Stiffening: A Review

BACKGROUND

Arterial stiffening is a hallmark of vascular ageing and a consequence of many diseases including diabetes mellitus. Methylglyoxal (MGO), a highly reactive α-dicarbonyl mainly formed during glycolysis, has emerged as a potential contributor to the development of arterial stiffness. MGO reacts with arginine and lysine residues in proteins to form stable advanced glycation endproducts (AGEs). AGEs may contribute to arterial stiffening by increased cross-linking of collagen within the extracellular matrix (ECM), by altering the vascular structure, and by triggering inflammatory and oxidative pathways. Although arterial stiffness is mainly determined by ECM and vascular smooth muscle cell function, the effects of MGO and MGO-derived AGEs on these structures have not been thoroughly reviewed to date.

METHODS AND RESULTS

We conducted a PubMed search without filtering for publication date which resulted in 16 experimental and 22 clinical studies eligible for inclusion. Remarkably, none of the experimental and only three of the clinical studies specifically mentioned MGO-derived AGEs. Almost all studies reported an association between arterial stiffness and AGE accumulation in the arterial wall or increased plasma AGEs. Other studies report reduced arterial stiffness in experimental models upon administration of AGE-breakers.

CONCLUSIONS

No papers published to date directly show an association between MGO or MGO-derived AGEs and arterial stiffening. The relevance of the various underlying mechanisms is not yet clear, which is particularly due to methodological challenges in the detection of MGO and MGO-derived AGEs at the molecular, intra- and pericellular, and structural levels, as well as in challenges in the assessment of intrinsic arterial wall properties at ECM- and tissue levels.

Carotid-femoral pulse wave velocity is significantly increased in newly diagnosed hypertensive patients with primary hyperparathyroidism and significantly related with serum calcium level

BACKGROUND

Primary hyperparathyroidism (PHP) is a rare cause of secondary hypertension (HT), but in patients with PHP, HT is very common and 20-80% of patients have HT. The aim of this study was to evaluate the change in carotid-femoral pulse wave velocity (CF-PWV) in hypertensive patients with PHP, and was to determine the clinical, laboratory, and echocardiographic parameters associated with CF-PWV.

METHODS

The study included 83 newly diagnosed hypertensive patients with PHP and 83 patients with newly diagnosed essential HT without PHP. All patients underwent echocardiography and CF-PWV measurements.

RESULTS

In patients with PHP, blood urea nitrogen, hs-CRP, uric acid, serum and urine calcium, parathyroid hormone level, CF-PWV value, LV wall thickness, LVMI, aortic and left atrium (LA) diameter, and presence of LVH and CF-PWV > 10 m/s were higher, and serum phosphorus levels were lower. Serum calcium, LA diameter, and LVMI values were closely correlated with CF-PWV. In the ROC analysis, the AUROC was calculated as 0.825 for calcium level to determine the patients with increased CF-PWV. When the serum calcium value was taken as 10 mg/dL, it was determined with CF-PWV > 10 m/s were 79.5% sensitivity and 78.2% specificity.

CONCLUSION

CF-PWV significantly increases in newly diagnosed hypertensive patients with PHP and significantly related to serum calcium level. To protect against target organ damage, high serum calcium levels should be monitored as well as blood pressure in hypertensive patients with PHP.

Augmentation index is not a proxy for wave reflection magnitude: mechanistic analysis using a computational model

The augmentation index (AIx) is deemed to capture the deleterious effect on left ventricular (LV) work of increased wave reflection associated with stiffer arteries. However, its validity as a proxy for wave reflection magnitude has been questioned. We hypothesized that, in addition to increased wave reflection due to increased pulse wave velocity, LV myocardial shortening velocity influences AIx. Using a computational model of the circulation, we investigated the isolated and combined influences of myocardial shortening velocity v_s,LV and arterial stiffness on AIx. Aortic blood pressure waveforms were characterized using AIx and the reflected wave pressure amplitude (p^bw, obtained using wave separation analysis). Our reference simulation (normal v_s,LV and arterial stiffness) was characterized by an AIx of 21%. A realistic reduction in v_s,LV caused AIx to increase from 21 to 42%. An arterial stiffness increase, characterized by a relevant 1.0 m/s increase in carotid-femoral pulse wave velocity, caused AIx to increase from 21 to 41%. Combining the reduced v_s,LV and increased arterial stiffness resulted in an AIx of 54%. In a multistep parametric analysis, both v_s,LV and arterial stiffness were about equal determinants of AIx, whereas p^bw was only determined by arterial stiffness. Furthermore, the relation between increased AIx and LV stroke work was only ≈50% explained by an increase in arterial stiffness, the other factor being v_s,LV. The p^bw, on the other hand, related less ambiguously to LV stroke work. We conclude that the AIx reflects both cardiac and vascular properties and should not be considered an exclusively vascular parameter.

NEW & NOTEWORTHY We used a state-of-the-art computational model to mechanistically investigate the validity of the augmentation index (AIx) as a proxy for (changes in) wave reflection. In contrary to current belief, we found that LV contraction velocity influences AIx as much as increased arterial stiffness, and increased AIx does not necessarily relate to an increase in LV stroke work. Wave reflection magnitude derived from considering pressure, as well as flow, does qualify as a determinant of LV stroke work.