Longitudinal Measures of Blood Pressure and Subclinical Atrial Arrhythmias: The MESA and the ARIC Study

Blood pressure fragmentation as a new measure of blood pressure variability: association with predictors of cardiac surgery outcomes

Background: Fluctuations in beat-to-beat blood pressure variability (BPV) encode untapped information of clinical utility. A need exists for developing new methods to quantify the dynamical properties of these fluctuations beyond their mean and variance. Objectives: Introduction of a new beat-to-beat BPV measure, termed blood pressure fragmentation (BPF), and testing of whether increased preoperative BPF is associated with (i) older age; (ii) higher cardiac surgical risk, assessed using the Society of Thoracic Surgeons' (STS) Risk of Morbidity and Mortality index and the European System for Cardiac Operative Risk Evaluation Score (EuroSCORE II); and (iii) longer ICU length of stay (LOS) following cardiac surgery. The secondary objective was to use standard BPV measures, specifically, mean, SD, coefficient of variation (CV), average real variability (ARV), as well a short-term scaling index, the detrended fluctuation analysis (DFA) ⍺1 exponent, in the same type of analyses to compare the results with those obtained using BPF. Methods: Consecutive sample of 497 adult patients (72% male; age, median [inter-quartile range]: 67 [59-75] years) undergoing cardiac surgery with cardiopulmonary bypass. Fragmentation, standard BPV and DFA ⍺1 measures were derived from preoperative systolic blood pressure (SBP) time series obtained from radial artery recordings. Results: Increased preoperative systolic BPF was associated with older age, higher STS Risk of Morbidity and Mortality and EuroSCORE II values, and longer ICU LOS in all models. Specifically, a one-SD increase in systolic BPF (9%) was associated with a 26% (13%-40%) higher likelihood of longer ICU LOS (>2 days). Among the other measures, only ARV and DFA ⍺1 tended to be associated with longer ICU LOS. However, the associations did not reach significance in the most adjusted models. Conclusion: Preoperative BPF was significantly associated with preoperative predictors of cardiac surgical outcomes as well as with ICU LOS. Our findings encourage future studies of preoperative BPF for assessment of health status and risk stratification of surgical and non-surgical patients.

Higher Cumulative Blood Pressure in Midlife Predicts an Increased Risk of Atrial Fibrillation: Evidence From the Atherosclerosis Risk in Communities Study

BACKGROUND

Elevated blood pressure (BP) is reportedly associated with an increased risk of atrial fibrillation (AF). However, the association between cumulative BP exposure in midlife and incident AF in mid-to-late life remains unclear.

METHODS AND RESULTS

Participants enrolled in the ARIC (Atherosclerosis Risk in Communities) study with 4 consecutive BP measurements and no prevalent AF at baseline were included. Cumulative BP was calculated as the area under the curve from visit 1 to visit 4. Incident AF was identified by study visit ECGs, hospital discharge codes, or death certificates. A total of 9892 participants were included (44.6% men and mean age 62.9±5.7 years at visit 4) with 1550 (15.7%) individuals who developed new-onset AF during an average follow-up of 15.4 years. The incidence rates of AF per 1000 person-years across the 4 quartiles of cumulative systolic BP were 7.9, 9.2, 12.5, and 16.9, respectively. After multivariable adjustment, the hazard ratios for incident AF among participants in the highest quartile of cumulative systolic BP, pulse pressure, and mean arterial pressure were 1.48 (95% CI, 1.27-1.72), 1.81 (95% CI, 1.53-2.13), and 1.22 (95% CI, 1.05-1.41), respectively, compared with those in the lowest quartile. The addition of cumulative systolic BP or pulse pressure slightly improved the ability to predict new-onset AF.

CONCLUSIONS

Higher exposure to cumulative systolic BP, pulse pressure, and mean arterial pressure was significantly associated with increased risk of incident AF.

Predictors of long-term absence of coronary artery calcium in individuals with high blood pressure: results from the MESA study

BACKGROUND & AIMS

Individuals with high blood pressure (BP) have varying risks of cardiovascular events due to other coexisting factors. We aimed to identify the predictors of long-term absence of coronary artery calcium (CAC) in individuals with high BP, which is an indicator of healthy arterial aging and can guide preventive strategies.

METHODS

We analyzed data from participants with high BP (≥120/80 mm Hg) in the Multi-Ethnic Study of Atherosclerosis who had baseline CAC = 0 and underwent a second CAC scanning after 10 years. We used multivariable logistic regression to evaluate the association between various risk factors for atherosclerotic cardiovascular disease (ASCVD) and long-term CAC = 0. We also calculated the area under the receiver operating characteristic curve (AUC) to predict the phenotype of healthy arterial aging in this population.

RESULTS

We included 830 participants (37.6% male, mean ± SD age of 59.4 ± 8.7 years). During follow-up, 46.5% of participants (n = 386) had CAC = 0, and they were younger and had fewer metabolic syndrome components. Adding ASCVD risk factors to the demographic model (age, sex, and ethnicity) moderately increased the predictive value for long-term CAC = 0 (AUC: demographic model + ASCVD risk factors vs. demographic model alone, 0.653 vs. 0.597, p < .001; category net reclassification improvement = 0.104, p = .044; integrated discrimination improvement = 0.040, p < .001).

CONCLUSION

In individuals with high BP and initial CAC = 0, over 40% maintained CAC = 0 during a 10-year follow-up, which was associated with fewer ASCVD risk factors. These findings may have implications for preventive strategies in individuals with high BP.Clinical Trial registration number: The MESA was registered at clinical trials. gov as NCT00005487.KEY MESSAGESNearly half (46.5%) of individuals with high blood pressure (BP) maintained a long-term absence of coronary artery calcium (CAC) during a 10-year follow-up, and this was associated with a 66.6% lower risk of atherosclerotic cardiovascular disease (ASCVD) events compared to those who developed incident CAC.Individuals with high BP, who are usually assumed to have an increased risk of ASCVD, exhibit significant heterogeneity in their ASCVD risk; those who maintain CAC = 0 have a lower ASCVD risk.Adding overall ASCVD risk factors to demographic information resulted in a moderate improvement in predicting long-term CAC = 0.