Increasing prevalence of hypertension among patients with thoracic aorta dissection: trends over eight decades--a structured meta-analysis

Greater TIMP-1 protein levels and neointimal formation represent sex-dependent cellular events limiting aortic vessel expansion in female rats

Fragmentation/loss of the structural protein elastin represents the precipitating event translating to aortic expansion and subsequent aneurysm formation. The present study tested the hypothesis that greater protein expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and neointimal growth secondary to a reduction of medial elastin content represent sex-dependent events limiting aortic vessel expansion in females. TIMP-1 protein levels were higher in the ascending aorta of female versus male patients diagnosed with a bicuspid aortic valve (BAV). The latter paradigm was recapitulated in the aorta of adult male and female rats complemented by greater TIMP-2 expression in females. CaCl2 (0.5 M) treatment of the infrarenal aorta of adult male and female rats increased the in situ vessel diameter and expansion was significantly smaller in females despite a comparable reduction of medial elastin content. The preferential appearance of a neointimal region of the CaCl2-treated infrarenal aorta of female rats may explain in part the smaller in situ expansion and neointimal growth correlated positively with the % change of the in situ diameter. Neointimal formation was secondary to a significant increase in the density of medial/neointimal vascular smooth muscle cells (VSMCs) that re-entered the G2-M phase whereas VSMC cell cycle re-entry was attenuated in the CaCl2-treated infrarenal aorta of male rats. Thus, greater TIMP-1 expression in the aorta of female BAV patients may prevent excessive elastin fragmentation and preferential neointimal growth following CaCl2-treatment of the infrarenal aorta of female rats represents a sex-dependent biological event limiting vessel expansion secondary to a significant loss of the structural protein.

The ascending aorta of male hypertensive bicuspid aortic valve patients preferentially associated with a cellular aneurysmal phenotype

Male sex and hypertension represent risk factors in the progression of an aortic aneurysm. The present study examined the morphological/cellular phenotype of the ascending aorta (AA) of male and female patients diagnosed with a bicuspid aortic valve (BAV) to test the hypothesis that hypertension-induced remodeling of male BAV patients preferentially recapitulated the expression of a panel of proteins favoring aneurysm formation. The diameter of the AA of hypertensive male (35 ± 6 mm) and female (39 ± 5 mm) BAV patients was comparable to normotensive patients reflecting an early phase of vessel expansion. Morphological/structural remodeling of the medial region of the AA of male normotensive and hypertensive BAV patients were comparable. Protein levels of non-muscle myosin IIB, the cell cycle inhibitor p27kip1, tumor suppressor p53 and matrix metalloproteinase-2 and -9 were significantly upregulated in the AA of male hypertensive BAV patients. In female hypertensive BAV patients, collagen content was significantly increased whereas elastin content and medial width of the AA were similar to normotensive BAV patients. In the AA of female hypertensive BAV patients, matrix metalloproteinase-9 and p27kip1 protein levels were unchanged whereas p53 and matrix metalloproteinase-2 protein expression was significantly reduced. Nestin protein levels were diminished in the AA of male and female hypertensive BAV patients. Thus, sexual dimorphic remodeling of the AA was prevalent in hypertensive BAV patients. Moreover, during the early phase of vessel expansion, the AA of male hypertensive BAV patients was preferentially associated with the upregulation of a panel of proteins linked to progressive dilatation and potential aneurysm formation.

Central Hypertension in Patients With Thoracic Aortic Aneurysms: Prevalence and Association With Aneurysm Size and Growth

BACKGROUND

Hypertension (HTN) has the greatest population-attributable risk for aortic dissection and is highly prevalent among patients with thoracic aortic aneurysms (TAAs). Although HTN is diagnosed based on brachial blood pressure (bBP), central HTN (central systolic blood pressure [cSBP] ≥130 mm Hg) is of interest as it better reflects blood pressure (BP) in the aorta. We aimed to (i) evaluate the prevalence of central HTN among TAA patients without a diagnosis of HTN, and (ii) assess associations of bBP vs. central blood pressure (cBP) with aneurysm size and growth.

METHODS

One hundred and five unoperated subjects with TAAs were recruited. With validated methodology, cBP was assessed with applanation tonometry. Aneurysm size was assessed at baseline and follow-up using imaging modalities. Aneurysm growth rate was calculated in mm/year. Multivariable linear regression adjusted for potential confounders assessed associations of bBP and cBP with aneurysm size and growth.

RESULTS

Seventy-seven percent of participants were men and 49% carried a diagnosis of HTN. Among participants without diagnosis of HTN, 15% had central HTN despite normal bBP ("occult central HTN"). In these patients, higher central systolic BP (cSBP) and central pulse pressure (cPP) were independently associated with larger aneurysm size (β ± SE = 0.28 ± 0.11, P = 0.014 and cPP = 0.30 ± 0.11, P = 0.010, respectively) and future aneurysm growth (β ± SE = 0.022 ± 0.008, P = 0.013 and 0.024 ± 0.009, P = 0.008, respectively) while bBP was not (P > 0.05).

CONCLUSIONS

In patients with TAAs without a diagnosis of HTN, central HTN is prevalent, and higher cBP is associated with larger aneurysms and faster aneurysm growth.

Aortic Dissections in the Population-Based Danish National Patient Registry from 1996–2016: A Validation Study

Purpose

This study evaluated the validity of the ICD-10 diagnostic codes for aortic dissections (ADs) in the Danish National Patient Registry (DNPR) based upon positive predictive values (PPV).

Patients and methods

Cases registered in the DNPR with the unspecific AD diagnostic code DI710 (unspecified AD) from 1996 to 2016, and the specific AD diagnostic codes DI710A (AD Type A) and DI710B (AD Type B) from 2006 to 2016, were included. Available medical records from all registered cases underwent review. Confirmed cases of AD served as “gold standard” when reporting PPV. PPV estimates were stratified by regional differences, date, age at time of diagnosis, and sex.

Results

A total of 5018 cases were identified in the DNPR. After merging of data and retrieval of medical records, 3767 cases were eligible for validation. Of these, 2677 cases were verified as AD type A (59.7%), AD type B (38.8%), and unspecified type of AD (1.5%). The average age at diagnosis was 65.1 ±13.0 years (67.3% males). The overall PPV for having an AD when one of the three diagnostic codes were registered from 1996 to 2016 was 71.1% (95% confidence interval (CI): 69.6–72.5) and increased significantly over time. From 2006 to 2016, the PPV for the specific AD diagnostic codes was 89.5% (95% CI: 87.4–91.3), whilst the PPV for the unspecific diagnostic code was 63.5% (95% CI: 61.1–65.9).

Conclusion

We found the overall PPV for the pooled AD diagnostic codes in the DNPR acceptable. However, the two specific AD diagnostic codes presented remarkably higher PPV compared to the unspecific diagnostic code.

CRP immunodeposition and proteomic analysis in abdominal aortic aneurysm

OBJECTIVE

The molecular mechanisms of the degeneration of the aortic wall in abdominal aortic aneurysm (AAA) are poorly understood. The monomeric form of C-reactive protein (mCRP) is deposited in damaged cardiovascular organs and aggravates the prognosis; however, it is unknown whether mCRP is deposited in the degenerated aorta of abdominal aortic aneurysm (AAA). We investigated whether mCRP is deposited in AAA and examined the associated pathogenic signaling pathways.

METHODS

Twenty-four cases of AAA were analyzed and their histological features were compared according to the level of serum CRP and the degree of mCRP deposition. Proteomic analysis was performed in AAA cases with strong and diffuse CRP immunopositivity (n = 7) and those with weak, focal, and junctional CRP immunopositivity (n = 3).

RESULTS

mCRP was deposited in the aortic specimens of AAA in a characteristic pattern that coincided with the lesion of the diminished elastic layer of the aortic wall. High serum CRP level was associated with stronger mCRP immunopositivity and a larger maximal diameter of aortic aneurysm. Proteomic analysis in AAA showed that multiple proteins were differentially expressed according to mCRP immunopositivity. Also, ingenuity pathway analysis showed that pathways associated with atherosclerosis, acute phase response, complement system, immune system, and coagulation were enriched in AAA cases with high mCRP immunopositivity.

CONCLUSIONS

AAA showed a characteristic deposition of mCRP, and multiple potentially pathologic signaling pathways were upregulated in AAA cases with strong CRP immunopositivity. mCRP and the aforementioned pathological pathways may serve as targets for managing the progression of AAA.

Bariatric surgery is associated with reduced admission for aortic dissection: a nationwide case-control analysis

BACKGROUND

Aortic dissection (AD) is an uncommon but life-threatening condition associated with high morbidity and mortality. Hypertension (HTN) and hyperlipidemia (HLD) are common modifiable risk factors.

OBJECTIVES

Since bariatric surgery is associated with remission of obesity-related co-morbidities, we hypothesize that surgical weight loss might be protective against this feared aortic pathology.

SETTING

A cross-sectional analysis was performed using the National Inpatient Sample database from 2010 to 2015.

METHODS

The treatment group included bariatric patients and the control group patients with obesity (body mass index [BMI] ≥ 35kg/m²) without previous bariatric surgery. Analyzed covariates included demographics, co-morbidities, aortic diseases, and AD. A multivariate logistic regression analysis (MLRA) was performed to assess the odds of admission for AD in both groups.

RESULTS

A total of 2,300,845 patients were identified (2,004,804 controls and 296,041 cases). The mean (SEM) age was 54.4 (.05) versus 51.9 (.05) years, for the control and treatment groups, respectively (P < .0001). Bariatric patients posed a significantly lower prevalence of type 2 diabetes (T2D), HTN, HLD, aortic aneurysm, and bicuspid aortic valve (P < .0001) than control subjects. In the control group, 1411 individuals (.070%) had AD, whereas only 94 patients (.032%) in the bariatric surgery group had such diagnosis (P < .0001). The MLRA showed that non-bariatric obese patients had a significantly higher likelihood of suffering from AD (OR = 1.8 [95%CI 1.44-2.29] P < .0001). Considering different age groups, bariatric surgery was found to be less associated with admission for AD for individuals below and above 40 years of age (OR = 2.95 [95%CI 1.09-7.99] P = .0345) and (OR = 1.75 [95%CI 1.38-2.22] P < .0001), respectively.

CONCLUSIONS

Bariatric surgery could be a protective factor against aortic dissection and should be considered in patients with obesity and risk factors for this cardiovascular complication.

Impact of hypertension on short- and long-term survival of patients who underwent emergency surgery for type A acute aortic dissection

Background

To explore the clinical characteristics and prognosis of patients with hypertension underwent emergency surgery for type A acute aortic dissection (TA-AAD).

Methods

The present study enrolled 712 consecutive patients diagnosed with TA-AAD and received aortic repair surgery at our hospital between January 2014 to December 2018. Clinical characteristics of enrolled patients were retrospectively reviewed. Patients were grouped by preexisting hypertension history and matched with propensity scores matching method. Patients’ clinical characteristics were compared and analyzed before and after propensity scoring. To identify predictors for long-term mortality rate, Kaplan-Meier survival estimation and Cox proportional hazard analysis were performed.

Results

A total of 492 patients (69.1% of all patients in the cohort) were included in the hypertensive group and they had increased age and weight compared to patients in the non-hypertensive group. Between two groups, preoperative leukocyte count and serum creatinine level were found significant different (P<0.05). After propensity scoring, 128 pairs (256 patients) were successfully matched. Our analysis showed that there was no significant difference of ventilation duration, 30-day mortality rate, intensive care unit stay and hospitalization time between two groups. However, our data suggested that hypertensive patients presented with less intra-operative aortic valve involvement. There was a significant difference in long-term survival rate (P=0.037) between two groups. Cox regression analysis demonstrated that hypertension was an independent risk factor [hazard ratio (HR), 3.040; 95% confidence interval (CI), 1.124–8.227; P=0.029].

Conclusions

Our data suggested that TA-AAD patients complicated with hypertension had increased age and weight compared to non-hypertensive patients. Concomitant hypertension identified upon hospital administration was an independent risk factor for long-term survival in TA-AAD patients while did not influence the 30-day mortality rate.

Alcohol Consumption and Aortic Root Dilatation: Insights from the Corinthia Study

Aortic diameter and progression to thoracic aortic aneurysm are influenced by several factors. In this study, we investigated the association of alcohol consumption with aortic root and ascending aorta dilatation. In the context of the Corinthia study, we examined 1751 patients with echocardiography. Several demographic and clinical characteristics were recorded. Alcohol consumption was assessed based on a questionnaire of frequency, type, and quantity. Accordingly, patients were categorized as everyday alcohol consumers (EDACs) and as social drinkers (SoD). Everyday alcohol consumers were further categorized to group 1: 0 to 1 drink/d; group 2: 1 to 2 drinks/d; and group 3: ≥3 drinks/d. From the study population, 40% were categorized as EDAC and had an increased aortic root diameter (AoRD) and an elevated AoRD index compared with SoD. Interestingly, there was a stepwise increase in aortic root and ascending aorta diameter according to daily alcohol consumption. Specifically, patients consuming ≥3 drinks of alcohol/d had increased indexed aortic by 1.4 mm/m2 compared with SoD even after adjustment for possible confounders. Daily alcohol consumption is associated with increased aortic root diameter. These findings may have important clinical implications, especially in patients with borderline or dilated aortic root, and merit further investigation.

Heat shock protein 27 plays a protective role in thoracic aortic dissection by promoting cell proliferation and inhibiting apoptosis

Background

Thoracic aortic dissection (TAD) is one of the most severe aortic diseases. The study aimed to explore the potential role of heat shock protein 27 (HSP27) in the pathogenesis of TAD using an in vitro model of oxidative stress in vascular smooth muscle cells (VSMCs).

Methods

HSP27 was analyzed in aortic surgical specimens from 12 patients with TAD and 8 healthy controls. A lentiviral vector was used to overexpress HSP27 in rat aortic VSMCs. Cell proliferation and apoptosis were measured under oxidative stress induced by H₂O₂.

Results

HSP27 expression was significantly higher in aortic tissue from patients with TAD and VSMCs in the aortic media were the main cell type producing HSP27. Elevated oxidative stress was also detected in the TAD samples. Overexpression of HSP27 significantly attenuated H₂O₂-induced inhibition of cell proliferation. Furthermore, HSP27 was found to decrease H₂O₂-induced cell apoptosis and oxidative stress.

Conclusions

These results suggest that HSP27 expression promotes VSMC viability, suppresses cell apoptosis, and confers protection against oxidative stress in TAD.

Accentuating and Opposing Factors Leading to Development of Thoracic Aortic Aneurysms Not Due to Genetic or Inherited Conditions

Understanding and unraveling the pathophysiology of thoracic aortic aneurysm (TAA), a vascular disease with a potentially high-mortality rate, is one of the next frontiers in vascular biology. The processes leading to the formation of TAA, of unknown cause, so-called degenerative TAA, are complex. This review advances the concept of promoters and inhibitors of the development of degenerative TAA. Promoters of TAA development include age, blood pressure elevation, increased pulse pressure, neurohumeral factors increasing blood pressure, inflammation specifically IFN-γ, IL-1 β, IL-6, TNF-α, and S100 A12; the coagulation system specifically plasmin, platelets, and thrombin as well as matrix metalloproteinases (MMPs). SMAD-2 signaling and specific microRNAs modulate TAA development. The major inhibitors or factors opposing TAA development are the constituents of the aortic wall (elastic lamellae, collagen, fibulins, fibronectin, proteoglycans, and vascular smooth muscle cells), which maintain normal aortic dimensions in the face of aortic wall stress, specific tissue MMP inhibitors, plasminogen activator inhibitor-1, protease nexin-1, and Syndecans. Increases in promoters and reductions in inhibitors expand the thoracic aorta leading to TAA formation.

C-reactive protein, not cardiac troponin T, improves risk prediction in hypertensives with type A aortic dissection

BACKGROUND

The aim of the study was to evaluate prognostic role of inflammatory biomarkers, cardiac troponin T (cTnT) and D-dimer in type A acute aortic dissection (AAD) and to examine whether they might help in risk stratification beyond values of International Registry of Acute Aortic Dissection (IRAD) score.

METHODS

Baseline biomarkers were determined in 54 consecutive predominantly hypertensive patients with type A AAD and evaluated for in-hospital mortality.

RESULTS

After multivariable adjustment, the independent predictors of outcome were age (OR = 1.09; 95% CI 1.02-1.18), treatment strategy (OR = 0.11; 95% CI 0.02-0.06) and C-reactive protein (CRP) either as binary (OR = 7.06; 95% CI 1.34-37.36) or continuous variable (OR = 1.10; 95% CI 1.01-1.21). cTnT did not independently influence mortality. Receiver- operating characteristic (ROC) curve analysis showed significant link between CRP and outcome (area under the ROC curve, AUC = 0.79; p < 0.01). Values of CRP > 9.8 mg/l had 83% sensitivity and 80% specificity for predicting in-hospital mortality. Addition of CRP to IRAD score improved prediction of short-term outcome, AUC increased from 0.74 to 0.89 (p = 0.004).

CONCLUSION

Admission CRP has independent prognostic value in type A AAD and the addition of CRP to IRAD score improved discriminative capacity of in-hospital mortality irrespective of symptom duration and treatment strategy.

FBN1 polymorphisms in patients with the dilatative pathology of the ascending thoracic aorta

OBJECTIVES

To investigate polymorphisms of the fibrillin-1 (FBN1) gene (namely, rs2118181, rs1036477, rs10519177, rs755251 and rs4774517) in a case-control study for dilatative pathology of the ascending thoracic aorta (DPATA) from Lithuanians.

METHODS

We studied 312 patients who had undergone aortic reconstructive surgery for DPATA. These patients were sub-divided according to the phenotypes of their DPATA into (i) ascending aortic aneurysm (n = 160), (ii) post-stenotic dilatation of the ascending aorta due to aortic valve stenosis (n = 79) and (iii) Stanford A dissection (n = 73). The reference group (n = 472) was recruited from a random sample screened within epidemiological studies of the Lithuanian population. FBN1 polymorphisms were studied by real-time polymerase-chain-reaction amplification.

RESULTS

Patients within the aortic dissection sub-group had significantly higher minor allele frequencies in all five FBN1 single nucleotide polymorphism (SNPs) studied versus reference group subjects (P < 0.0001). Minor allele frequencies in SNPs rs2118181, rs1036477 were significantly higher in those with aortic aneurysm when compared with the reference group (P = 0.007). Thus, minor alleles of FBN1 SNPs studied were significantly associated with aortic dissection with odds ratios (ORs) 2.59-2.13, P < 0.001, while SNPs rs2118181 and rs1036477 with an increased risk of ascending aortic aneurysm [OR 1.67, confidence interval (CI) 95% 1.61-2.40]. The association of FBN1 genotypes with each phenotype of DPATA was assessed using logistic regression models adjusted for gender, age and hypertension. The additive model best fitted SNPs rs2118181 and rs1036477 in association with the ascending aortic aneurysm sub-group (OR 1.70, CI 95% 1.17-2.46) or the Stanford A dissection sub-group (OR 2.64, CI 95% 1.66-4.19). A recessive model fitted best the association between SNPs rs10519177, rs755251, rs4774517 and Stanford A dissection (OR 4.31, CI 95% 2.06-9.01). There were no significant associations between all studied FBN1 SNPs and post-stenotic or bicuspid aortic dilatation.

CONCLUSIONS

Our study provides evidence for the following: (i) FBN1 SNPs rs2118181, rs1036477, rs10519177, rs4774517, rs755251 may increase susceptibility to aortic dissections and (ii) FBN1 SNPs rs2118181, rs1036477 to the formation of aortic aneurysms. Thus, these SNPs might be considered as biomarkers for identifying patients at risk for ascending aortic aneurysm and aortic dissection.

Myh11(R247C/R247C) mutations increase thoracic aorta vulnerability to intramural damage despite a general biomechanical adaptivity

Genetic studies in patients reveal that mutations to genes that encode contractile proteins in medial smooth muscle cells can cause thoracic aortic aneurysms and dissections. Mouse models of such mutations, including Acta2(-/-) and Myh11(R247C/R247C), surprisingly do not present with any severe vascular phenotype under normal conditions. This observation raises the question whether these mutations nevertheless render the thoracic aorta increasingly vulnerable to aneurysms or dissections in the presence of additional, epigenetic, factors such as hypertension, a known risk factor for thoracic aortic disease. Accordingly, we compared the structure and biaxial mechanical properties of the ascending and descending thoracic aorta from male wild-type and Myh11(R247C/R247C) mice under normotension and induced hypertension. On average, the mutant aortas exhibited near normal biomechanics under normotensive hemodynamics and near normal adaptations to hypertensive hemodynamics, yet the latter led to intramural delaminations or premature deaths in over 20% of these mice. Moreover, the delaminated vessels exhibited localized pools of mucoid material, similar to the common histopathologic characteristic observed in aortas from humans affected by thoracic aortic aneurysms and dissections. The present findings suggest, therefore, that mutations to smooth muscle cell contractile proteins may place the thoracic aorta at increased risk to epigenetic factors and that there is a need to focus on focal, not global, changes in aortic structure and properties, including the pooling of glycosaminoglycans/proteoglycans that may lead to thoracic aortic dissection.

First-line beta-blockers versus other antihypertensive medications for chronic type B aortic dissection

BACKGROUND

Thoracic aortic dissection (TAD) is a severe and often lethal complication in people with hypertension. Current practice in the treatment of chronic type B aortic dissections is the use of beta-blockers as first-line therapy to decrease aortic wall stress. Other antihypertensive medications, such as calcium channel blockers (CCBs), angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), have been suggested for the medical therapy of type B TAD.

OBJECTIVES

To assess the effects of first-line beta-blockers compared with other first-line antihypertensive drug classes for treating chronic type B TAD.

SEARCH METHODS

We searched the Database of Abstracts of Reviews of Effects (DARE) for related reviews. We searched the Hypertension Group Specialised Register (1946 to 26 January 2014), the Cochrane Central Register of Controlled Trials (2014, Issue 1), MEDLINE (1946 to 24 January 2014), MEDLINE In-Process, EMBASE (1974 to 24 January 2014) and ClinicalTrials.gov (to 26 January 2014).

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) comparing different antihypertensive medications in the treatment of chronic type B TAD to be eligible for inclusion. Total mortality rate was the primary outcome of this review. Secondary outcomes included total non-fatal adverse events relating to TADs and number of people not requiring surgical treatment.

DATA COLLECTION AND ANALYSIS

Two review authors (KC, PL) independently reviewed titles and abstracts and decided on studies to include based on the inclusion criteria. We resolved discrepancies between the two review authors by discussion.

MAIN RESULTS

After a thorough review of the search results, we identified no studies that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We did not find any RCTs that compared first-line beta-blockers with other first-line antihypertensive medications for the treatment of chronic type B TAD. Therefore, there is no RCT evidence to support the current guidelines recommending the use of beta-blockers. RCTs are required to assess the benefits and harms of beta-blockers and other antihypertensive medications as first-line treatment of chronic type B TAD.