The International Database of Central Arterial Properties for Risk Stratification: Research Objectives and Baseline Characteristics of Participants

Mortality and Cardiovascular End Points In Relation to the Aortic Pulse Wave Components: An Individual-Participant Meta-Analysis

BACKGROUND

Wave separation analysis enables individualized evaluation of the aortic pulse wave components. Previous studies focused on the pressure height with overall positive but differing results. In the present analysis, we assessed the associations of the pressure of forward and backward (Pfor and Pref) pulse waves with prospective cardiovascular end points, with extended analysis for time to pressure peak (Tfor and Tref).

METHODS

Participants in 3 IDCARS (International Database of Central Arterial Properties for Risk Stratification) cohorts (Argentina, Belgium, and Finland) aged ≥20 years with valid pulse wave analysis and follow-up data were included. Pulse wave analysis was done using the SphygmoCor device, and pulse wave separation was done using the triangular method. The primary end points consisted of cardiovascular mortality and nonfatal cardiovascular and cerebrovascular events. Multivariable-adjusted Cox regression was used to calculate hazard ratios.

RESULTS

A total of 2206 participants (mean age, 57.0 years; 55.0% women) were analyzed. Mean±SDs for Pfor, Pref, Tfor, and Tfor/Tref were 31.0±9.1 mm Hg, 20.8±8.4 mm Hg, 130.8±35.5, and 0.51±0.11, respectively. Over a median follow-up of 4.4 years, 146 (6.6%) participants experienced a primary end point. Every 1 SD increment in Pfor, Tfor, and Tfor/Tref was associated with 27% (95% CI, 1.07-1.49), 25% (95% CI, 1.07-1.45), and 32% (95% CI, 1.12-1.56) higher risk, respectively. Adding Tfor and Tfor/Tref to existing risk models improved model prediction (∆Uno's C, 0.020; P<0.01).

CONCLUSIONS

Pulse wave components were predictive of composite cardiovascular end points, with Tfor/Tref showing significant improvement in risk prediction. Pending further confirmation, the ratio of time to forward and backward pressure peak may be useful to evaluate increased afterload and signify increased cardiovascular risk.

Age and Sex Differences in the Contribution of Mean Arterial Pressure to Pulse Pressure Before Middle Age

INTRODUCTION

A lower ability to buffer pulse pressure (PP) in the face of increasing mean arterial pressure (MAP) may underlie the disproportionate increase in systolic blood pressure (SBP) in women from young adulthood through middle-aged relative to men.

AIM

To evaluate the contribution of MAP to the change in PP and pressure wave contour in men and women from young adulthood to middle age.

METHODS

Central pressure waveform was obtained from radial artery applanation tonometry in 312 hypertensive patients between 16 to 49 years (134 women, mean age 35 ± 9 years), 185 of whom were on antihypertensive treatment.

RESULTS

Higher MAP levels (≥ 100 mmHg) were significantly associated with higher brachial and central SBP (P < 0.001), PP (P < 0.001), incident wave (P = 0.005), AP (P < 0.001), and PWV (P < 0.001) compared to lower MAP levels. The relationship between MAP and brachial PP (P < 0.001), central PP (P < 0.001), incident wave (P < 0.001), and AP (P < 0.01), but not PWV, strengthens with age. The age-related increase in the contribution of MAP to brachial PP (P < 0.001), central PP (P < 0.001), and incident wave (P < 0.001) was more prominent in women than in men beginning in the fourth decade. In multiple regression analyses, MAP remained a significantly stronger predictor of central PP and incident wave in women than in men, independent of age, heart rate, and antihypertensive treatment. In turn, age remained a significantly stronger predictor of central PP and incident wave in women than in men, independent of MAP, heart rate, and antihypertensive treatment.

CONCLUSIONS

Women of reproductive age showed a steeper increase in PP with increasing MAP, despite comparable increases in arterial stiffness in both sexes. The difference was driven by a greater contribution of MAP to the forward component of the pressure wave in women.

Derivation of an Outcome-Driven Threshold for Aortic Pulse Wave Velocity: An Individual-Participant Meta-Analysis

BACKGROUND

Aortic pulse wave velocity (PWV) predicts cardiovascular events (CVEs) and total mortality (TM), but previous studies proposing actionable PWV thresholds have limited generalizability. This individual-participant meta-analysis is aimed at defining, testing calibration, and validating an outcome-driven threshold for PWV, using 2 populations studies, respectively, for derivation IDCARS (International Database of Central Arterial Properties for Risk Stratification) and replication MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease Health Survey - Copenhagen).

METHODS

A risk-carrying PWV threshold for CVE and TM was defined by multivariable Cox regression, using stepwise increasing PWV thresholds and by determining the threshold yielding a 5-year risk equivalent with systolic blood pressure of 140 mm Hg. The predictive performance of the PWV threshold was assessed by computing the integrated discrimination improvement and the net reclassification improvement.

RESULTS

In well-calibrated models in IDCARS, the risk-carrying PWV thresholds converged at 9 m/s (10 m/s considering the anatomic pulse wave travel distance). With full adjustments applied, the threshold predicted CVE (hazard ratio [CI]: 1.68 [1.15-2.45]) and TM (1.61 [1.01-2.55]) in IDCARS and in MONICA (1.40 [1.09-1.79] and 1.55 [1.23-1.95]). In IDCARS and MONICA, the predictive accuracy of the threshold for both end points was ≈0.75. Integrated discrimination improvement was significant for TM in IDCARS and for both TM and CVE in MONICA, whereas net reclassification improvement was not for any outcome.

CONCLUSIONS

PWV integrates multiple risk factors into a single variable and might replace a large panel of traditional risk factors. Exceeding the outcome-driven PWV threshold should motivate clinicians to stringent management of risk factors, in particular hypertension, which over a person's lifetime causes stiffening of the elastic arteries as waypoint to CVE and death.

The effect of SGLT2 inhibitors, GLP1 agonists, and their sequential combination on cardiometabolic parameters: A randomized, prospective, intervention study

BACKGROUND

Pulse wave velocity (PWV) and augmentation index (AIx) are indices used to assess arterial stiffness. We aim to compare the effect of empagliflozin, liraglutide and their sequential combination on arterial stiffness indices in patients with type 2 diabetes (T2D).

METHODS

This was a randomized single blind study evaluating the effect of empagliflozin vs liraglutide in adult patients with T2D. Patients were randomized to liraglutide titrated gradually to 1.8 mg or empagliflozin 25 mg in 1:1 ratio. Three months later empagliflozin was added to the liraglutide group, and liraglutide was added to the empagliflozin group. Patients were assessed with non-invasive tests for arterial stiffness (i.e., carotid-femoral PWV and AIx of aortic pressure) at baseline, 3-month and 9-month visits (final visit was extended for 3 months from the initial design due to Covid 19 pandemic). The primary outcome was the between-group difference of PWV change (ΔPWV) and ΔAIx at 3 months. Secondary outcomes included the between-group difference of ΔPWV and ΔAIx at 9 months, as well as the ΔPWV and ΔAIx between baseline and 9-month visit when total study population was assessed.

RESULTS

A total of 62 patients with T2D (30 started liraglutide; 32 empagliflozin, mean age 63 years, 25 % with established cardiovascular disease) participated in the study. We failed to show any significant between-group differences of ΔPWV and ΔΑΙx at 3 and 9 months, as well as between-group difference of ΔPWV and ΔAIx for the total study population between baseline and 9-month visit. In contrast, systemic vascular resistance and lipoprotein(a) levels improved, showing better results with liraglutide than empagliflozin. Favorable effects were also observed on body weight, body mass index, body and visceral fat, blood pressure, HbA1c, and uric acid levels.

CONCLUSION

No evidence of a favorable change in arterial stiffness indices was seen with empagliflozin or liraglutide or their combination in this study. Well-designed powerful studies are needed to address any potential effects on arterial stiffness in selected populations.

Central hypertension is a non-negligible cardiovascular risk factor

High blood pressure (BP) confers cardiovascular risk. However, the clinical value of central BP remains debatable. In this article, we aim to briefly review the prognosis, diagnosis, and treatment of central hypertension. Central and brachial BPs are closely correlated. In most prospective investigations, elevated central and peripheral BPs were similarly associated with adverse outcomes. Outcome-driven thresholds of the central systolic BP estimated by the type I device were on average 10 mmHg lower than their brachial counterparts. Cross-classification based on the central and brachial BPs identified that nearly 10% of patients had discrepancy in their status of central and brachial hypertension. Irrespective of the brachial BP status, central hypertension was associated with increased cardiovascular risk, highlighting the importance of central BP assessment in the management of hypertensive patients. Newer antihypertensive agents, such as renin-angiotensin-aldosterone system inhibitors and calcium channel blockers, were more efficacious than older agents in central BP reduction. Clinical trials are warranted to demonstrate whether controlling central hypertension with an optimized antihypertensive drug treatment will be beneficial beyond the control of brachial hypertension.

Risk Stratification by Cross-Classification of Central and Brachial Systolic Blood Pressure

BACKGROUND

Whether cardiovascular risk is more tightly associated with central (cSBP) than brachial (bSBP) systolic pressure remains debated, because of their close correlation and uncertain thresholds to differentiate cSBP into normotension versus hypertension.

METHODS

In a person-level meta-analysis of the International Database of Central Arterial Properties for Risk Stratification (n=5576; 54.1% women; mean age 54.2 years), outcome-driven thresholds for cSBP were determined and whether the cross-classification of cSBP and bSBP improved risk stratification was explored. cSBP was tonometrically estimated from the radial pulse wave using SphygmoCor software.

RESULTS

Over 4.1 years (median), 255 composite cardiovascular end points occurred. In multivariable bootstrapped analyses, cSBP thresholds (in mm Hg) of 110.5 (95% CI, 109.1-111.8), 120.2 (119.4-121.0), 130.0 (129.6-130.3), and 149.5 (148.4-150.5) generated 5-year cardiovascular risks equivalent to the American College of Cardiology/American Heart Association bSBP thresholds of 120, 130, 140, and 160. Applying 120/130 mm Hg as cSBP/bSBP thresholds delineated concordant central and brachial normotension (43.1%) and hypertension (48.2%) versus isolated brachial hypertension (5.0%) and isolated central hypertension (3.7%). With concordant normotension as reference, the multivariable hazard ratios for the cardiovascular end point were 1.30 (95% CI, 0.58-2.94) for isolated brachial hypertension, 2.28 (1.21-4.30) for isolated central hypertension, and 2.02 (1.41-2.91) for concordant hypertension. The increased cardiovascular risk associated with isolated central and concordant hypertension was paralleled by cerebrovascular end points with hazard ratios of 3.71 (1.37-10.06) and 2.60 (1.35-5.00), respectively.

CONCLUSIONS

Irrespective of the brachial blood pressure status, central hypertension increased cardiovascular and cerebrovascular risk indicating the importance of controlling central hypertension.