Lp(a) is not associated with arterial stiffness: a Mendelian randomization study

Background

Deeper understanding of the potential causal relationship between Lp(a) and vascular injury will provide further insight to related pathways to be monitored and targeted by emerging treatments. Accumulating evidence supports the causal association of lipoprotein(a) [Lp(a)] with cardiovascular disease and calcific aortic valve disease (AVD). Arterial stiffening is mechanistically linked with cardiovascular disease and AVD severity. We hypothesized that Lp(a) may be causally associated with pulse-wave velocity (PWV) as the gold-standard marker of arterial stiffness.

Aim

To investigate the potential causal association of Lp(a) levels with PWV.

Methods

We performed a two sample Mendelian randomization (MR) analysis of LP(a) on PWV by combining the summary data of two independent Genetic-Wide Association Study (GWASs). Genetic variants associated with Lp(a) were retrieved from the UK Biobank (N=220,497). A GWAS based on a cohort in Germany (N=7,000) was used to obtain genetic associations for PWV index (outcome). We assessed two different measures of arterial stiffness, brachial ankle (baPWV) and carotid femoral pulse (cfPWV) wave velocity. In total, we used 170 SNPs as Instrument Variables (IV's) and applied a two sample MR with the main technique of Inverse Variance Weighting method (IVW). We conducted sensitivity analyses (MR-Egger and Median based) to detect pleiotropy of the causal variants and to test for robustness of our findings.

Results

Our analyses based on all 170 SNP's did not find evidence for causal relationship between Lp(a) and PWV for neither measurement [bivw (baPWV) = −0.0005, CI (−0.0043, 0.0034), P=0.8 and bivw (cfPWV) = −0.006, CI (−0.013, 0.002), P=0.16 for brachial ankle and carotid-femoral PWV, respectively]. Sensitivity analyses, including weighted median and mode-based estimation, did not show significant association of Lp (a) with neither baPWV nor cfPWV.

Conclusions

Lp(a) is not causally associated with arterial stiffness. These findings suggest that arterial stiffening is not involved Lp(a)-mediated cardiovascular and aortic valve disease.

Funding Acknowledgement

Type of funding sources: None.

A systematic review and meta-analysis on the effect of selective serotonin reuptake inhibitors on endothelial function

Background

Depression and atherosclerotic cardiovascular disease (ASCVD) are commonly clustered in affected patients. Endothelial dysfunction is an early marker of ASCVD while also reported in patients with depression. Emerging evidence suggests that selective serotonin receptor inhibitors (SSRIs) may improve endothelial function. However, clinical studies assessing flow-mediated dilation (FMD), the gold-standard method to evaluate conduit artery endothelial function, in response to SSRIs treatment included limited number of patients and did not provide consistent results.

Purpose

In the present study we aim to evaluate the effect of SSRIs treatment on endothelial function assessed by longitudinal changes in FMD.

Methods

We performed a systematic review to retrieve and subsequently meta-analyze eligible studies in patients with depression who received SSRIs and had available measurements of FMD change before and after treatment.

Results

In 5 studies and 323 individuals in total, SSRIs were associated with increased FMD at the end of follow-up compared to baseline measurement (pooled mean change 1.97%, 95% CI 0.17, 3.77, P=0.032, I2=87.4%). These results did not substantially change when analysis was restricted to patients with history of atherosclerotic cardiovascular disease (ASCVD). Similarly, FMD changes were higher in individuals receiving SSRIs compared to not-treated subjects (pooled mean difference 2.5%. 95% CI 0.7, 4.2, P<0.001, I2=82.7%). Substantial heterogeneity regarding with respect to follow-up duration, demographics, and SSRIs agents.

Conclusion

SSRIs significantly improve FMD, the gold-standard marker of endothelial function. Further investigation is warranted for the role of FMD as a possible therapeutic biomarker in patients with depression and established or subclinical ASCVD.

Prospero registration: CRD42021252241

Funding Acknowledgement

Type of funding sources: None.

Carotid ultrasonography improves residual risk stratification in guidelines-defined high cardiovascular risk patients

Background

The clinical value of carotid atherosclerosis markers for residual risk stratification in high atherosclerotic cardiovascular disease (ASCVD) risk patients is not established.

Purpose

In the present study we aimed to derive and validate optimal values of markers of carotid subclinical atherosclerosis improving risk stratification in guidelines-defined high ASCVD risk patients.

Methods

We consecutively analysed high or very high ASCVD risk patients from a cardiovascular (CV) prevention registry (n=751, derivation cohort) and from the Atherosclerosis Risk in Communities (ARIC) study (n=2,897, validation cohort). Baseline ASCVD risk was defined using the 2021 European Society of Cardiology (ESC) guidelines (clinical ESCrisk). Intima-media thickness (IMT) excluding plaque, average maximal (avg.maxWT), maximal wall thickness (maxWT) and number of sites with carotid plaque were assessed. As endpoint of the study was defined the composite of CV death, acute myocardial infarction (MI) and revascularization after a median of 3.4 years in both cohorts and additionally for 16.7 years in the ARIC cohort.

Results

MaxWT >2.00mm and avg.maxWT >1.39mm provided incremental prognostic value, improved discrimination and correctly reclassified risk over the clinical ESCrisk both in the derivation and the validation cohort (p<0.05 for net reclassification index, integrated discrimination index and Delta Harrell's C index). MaxWT <0.9mm predicted very low probability of CV events (negative predictive value = 97% and 92% in the derivation and validation cohort, respectively). These findings were additionally confirmed for very long-term events in the validation cohort.

Conclusion

Integration of carotid ultrasonography in guidelines-defined risk stratification may identify very high risk patients in need for further residual risk reduction or at very low probability

Funding Acknowledgement

Type of funding sources: None.

Peripheral vascular involvement in transthyretin cardiac amyloidosis. A comparative analysis with AL amyloidosis

Background

The pattern of peripheral vascular involvement in the wild type transthyretin-related cardiac amyloidosis (ATTRwt) and its diagnostic utility in differentiating this infiltrating cardiomyopathy from light chain (AL) cardiac amyloidosis (AL-CA) and heart failure with preserved ejection fraction (HFpEF) of different origin have not been explored.

Aims

To characterize the pattern of peripheral vascular involvement in ATTRwt and evaluate its value in differentiating ATTRwt from AL-CA and HFpEF.

Methods

Newly diagnosed patients with ATTRwt (n=42) were consecutively recruited from our amyloidosis center. These patients were matched 1:1 for age and sex to patients with AL-CA (n=32) and subjects without amyloidosis (n=32) and also matched 2:1 to HFpEF patients (n=16). All subjects underwent a series of non-invasive vascular examinations for the assessment of: 1. subclinical carotid atherosclerosis with B-mode ultrasonography, 2. Arterial stiffness with measurement of carotid-femoral pulse wave velocity, 3. Reactive vasodilation with flow-mediated dilation (FMD) and 4. Aortic blood pressures and arterial wave reflections with augmentation index (AI) and return time of reflected wave (Tr).

Results

ATTRwt patients had lower peripheral (pBP) and aortic blood pressure (aBP) markers compared to non-AL controls (p<0.05 for all). ATTRwt grouping was an independent determinant of these markers, after adjustment for cardiovascular risk factors (CVRF), including history of hypertension, hyperlipidemia and diabetes, glomerular filtration rate, body mass index and smoking status (core model). ATTRwt had lower aDBP and increased Tr compared to AL subjects. In a comparison between ATTRwt and AL patients with cardiac involvement, AI and Tr were higher and FMD lower in ATTRwt patients. ATTRwt was an independent determinant of these markers, after adjustment for the core model (p<0.05 for all). Compared to HFpEF, patients with ATTRwt had lower peripheral and central BP and higher Tr (p<0.05 for all). By ROC analysis, Tr provided high diagnostic value for ATTRwt vs. AL-CA (Area Under the Curve, AUC=0.809, CI: 0.65–0.96) and for ATTRwt vs combined AL-CA and HFpEF (AUC=0.880, CI: 0.79–0.97). Finally, AI was closely correlated with posterior (Spearman's Rho=−0.30) and intraventricular wall thickness (Rho=−0.329) and left ventricular global longitudinal strain (Rho=−0.4) and lower cDBP with higher Gilmore and New York Heart Association stage (p<0.05).

Conclusion

ATTRwt patients present differential characteristics of peripheral vascular function and aortic hemodynamics as compared to AL, HFpEF and healthy controls. The clinical value of these characteristics merit further investigation since differential diagnosis among amyloidosis types is clinically challenging, while it may have prognostic implications.

Funding Acknowledgement

Type of funding sources: None.

Characterization and clinical implications of peripheral arterial involvement in transthyretin cardiac amyloidosis cardiomyopathy

Background

The sporadic form of transthyretin amyloidosis cardiomyopathy (ATTR-CM) is underdiagnosed but its prevalence is increasing due to the aging population. Given the poor prognosis of ATTR-CM understanding the underlying pathophysiologic mechanisms of the disease is imperative in order to improve strategies for early diagnosis and risk stratification and to develop new effective therapeutic options. ATTR-CM is associated with hypotension and there is preliminary experimental evidence of vascular involvement but its presence and clinical significance remains unknown.

Purpose

To characterize peripheral arterial involvement and explore its clinical role in ATTR-CM.

Methods

We consecutively recruited 28 previously untreated patients with newly diagnosed ATTR-CM and 34 elderly controls >70 years old, without ATTR-CM or heart failure. In both groups, flow-mediated dilatation (FMD) and intima-media thickness (IMT) in the carotid arteries were measured by high-resolution ultrasonography as markers of peripheral vascular reactivity and of subclinical atherosclerosis, respectively. Carotid-femoral pulse wave velocity (PWV) was measured as a marker of arterial stiffness. Aortic blood pressure (BP) and augmentation index (AI) using applanation tonometry were measured as markers of arterial wave reflections, peripheral arterial resistance and central hemodynamics. Echocardiography was performed in all ATTR patients. All cardiovascular (CV) measurements were performed before administration of any ATTR-specific therapy.

Results

ATTR patients were older and had lower prevalence of hypertension and male gender (p<0.05 for all) than the control group. Aortic and peripheral BP (p=0.016–0.088) and AI (p=0.003) were lower in ATTR patients. IMT in the common (cc) and internal carotid (ic) as well as in the carotid bulb (cb) were significantly higher in ATTR patients (p=0.001–0.042). After multivariable adjustment for traditional CV disease (CVD) risk factors, the ATTR group was independently associated with AI and IMT in cc, cb and ic (p<0.05 for all). In a subgroup of subjects with similar age between groups (n=13 and n=33 and 74.5±2.9 vs. 75.6±3.6 years, for ATTR vs. controls, respectively) differences in AI and cbIMT remained significant. Interestingly, AI was strongly and inversely associated with interventricular wall thickness (IVwt) in ATTR patients (spearman rho=−0.651, p=0.001). After adjustment for traditional CVD risk factors this association remained significant.

Conclusion

ATTR-CM is associated with lower aortic wave reflections, which correlate with more advanced structural cardiac disease, as assessed by IVwt. Further, ATTR-CM patients present accelerated subclinical carotid atherosclerosis as compared to elderly control subjects. These findings suggest that in ATTR-CM there is disease-specific peripheral vascular involvement in parallel to cardiac involvement. The clinical significance of these findings merits further investigation.

Funding Acknowledgement

Type of funding source: None

P2541Plasma levels of amyloid beta 1-40 are associated with the rate of progression of carotid subclinical atherosclerosis in postmenopausal women

Background

There is increasingly recognized undetected residual cardiovascular (CV) risk in postmenopausal women, suggesting the need for new risk biomarkers in this population. We have previously shown that amyloid-beta (1–40) (Aβ1–40), a proinflammatory and pro-atherosclerotic peptide, is associated with concurrent subclinical cardiovascular disease (CVD) in the general population and with major adverse cardiac events in patients with established cardiac disease. However, the clinical value of Aβ1–40 in menopause or whether this peptide is linked with an increased rate of progression of atherosclerotic disease is unknown.

Purpose

To examine the association of Aβ1–40 levels with the rate of progression of carotid intima-media thickness (IMT) in postmenopausal women.

Methods

In the settings of a Menopause Clinic, postmenopausal women (n=140) without clinically overt CVD or diabetes were consecutively recruited and re-evaluated after a median follow-up period of 24 months. IMT in the carotid arteries was measured by ultrasonography. The average of maximal IMT (mean cIMT) measured at both left and right common carotid, carotid bulb (cb)and internal carotid (ic) artery were used as the main end-point of the analysis. Aβ1–40 was measured in plasma samples at baseline and follow up. Fasting insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR).

Results

Women with increased plasma levels Aβ1–40 in the highest tertile presented the highest probability to have increased mean cIMT (adjusted OR=2.97, 95% CI 1.18–7.52, p=0.021) independently of age, smoke, hypertension, and hyperlipidemia. After adjustment for HOMA-IR, this association remained significant. Similarly, Aβ1–40 levels were associated with increased mean cb and icIMT (adjusted OR=3.34 for highest versus lower tertile, 95% CI 1.27–8.81, p=0.015). Mean cIMT significantly increased across the follow up period (0.73mm (0.065–0.08) to 0.77mm (0.07–0.089), median increase rate per year 0.024mm, p<0.001). By multi-level linear mixed model analysis, changes in Aβ1–40 levels were associated with increased rate of progression of mean cIMT (4.1% increase per 1-SD increase, p<0.001) after adjustment for differences in follow-up duration and age, hypertension, hyperlipidemia, and smoking. When repeated measurements of HOMA-IR were also considered, this association did not materially change (p=0.021). Similarly, longitudinal changes in Aβ1–40 correlated with the progression of mean cb and icIMT (3.9% increase per 1-SD increase, p=0.001), independently of time to re-evaluation and cardiovascular risk factors.

Conclusion

Aβ1–40 is an independent predictor of the rate of progression of subclinical carotid atherosclerosis in menopausal women. This finding supports the clinical value of Aβ1–40 in menopause and warrants further investigation for its prognostic role in this population.