Blood Pressure Measurement Device, Number and Timing of Visits, and Intra‐Individual Visit‐to‐Visit Variability of Blood Pressure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94447/1/jch.12005.pd

Effect of change in systolic blood pressure between clinic visits on estimated 10-year cardiovascular disease risk

Background Systolic blood pressure (SBP) often varies between clinic visits within individuals, which can affect estimation of cardiovascular disease (CVD) risk. Methods and Results We analyzed data from participants with two clinic visits separated by a median of 17 days in the Third National Health and Nutrition Examination Survey (n = 808). Ten-year CVD risk was calculated with SBP obtained at each visit using the Pooled Cohort Equations. The mean age of participants was 46.1 years, and 47.3% were male. The median SBP difference between the two visits was −1 mm Hg (1st to 99th percentiles: −23 to 32 mm Hg). The median estimated 10-year CVD risk was 2.5% and 2.4% at the first and second visit, respectively (1st to 99th percentiles −5.2% to +7.1%). Meaningful risk reclassification (ie, across the guideline recommended 7.5% threshold for statin initiation) occurred in 12 (11.3%) of 106 participants whose estimated CVD risk was between 5% and 10%, but only in two (0.3%) of 702 participants who had a 10-year estimated CVD risk of 10%. Conclusions SBP variability can affect CVD risk estimation, and can influence statin eligibility for individuals with an estimated 10-year CVD risk between 5% and 10%

Procedures for assessing psychological predictors of injuries in circus artists: a pilot prospective study

Background: Research on psychological risk factors for injury has focused on stable traits. Our objective was to test the feasibility of a prospective longitudinal study designed to examine labile psychological states as risk factors of injury. Methods: We measured psychological traits at baseline (mood, ways of coping and anxiety), and psychological states every day (1-item questions on anxiety, sleep, fatigue, soreness, self-confidence) before performances in Cirque du Soleil artists of the show “O”. Additional questions were added once per week to better assess anxiety (20-item) and mood. Questionnaires were provided in English, French, Russian and Japanese. Injury and exposure data were extracted from electronic records that are kept as part of routine business practices. Results: The 43.9% (36/82) recruitment rate was more than expected. Most artists completed the baseline questionnaires in 15 min, a weekly questionnaire in <2 min and a daily questionnaire in <1 min. We improved the formatting of some questions during the study, and adapted the wording of other questions to improve clarity. There were no dropouts during the entire study, suggesting the questionnaires were appropriate in content and length. Results for sample size calculations depend on the number of artists followed and the minimal important difference in injury rates, but in general, preclude a purely prospective study with daily data collection because of the long follow-up required. However, a prospective nested case-crossover design with data collection bi-weekly and at the time of injury appears feasible. Conclusion: A prospective study collecting psychological state data from subjects who train and work regularly together is feasible, but sample size calculations suggest that the optimal study design would use prospective nested case-crossover methodology

Relations Between QRS|T Angle, Cardiac Risk Factors, and Mortality in the Third National Health and Nutrition Examination Survey (NHANES III)

On the surface electrocardiogram, an abnormally wide QRS|T angle reflects changes in the regional action potential duration profiles and in the direction of the repolarization sequence, which is thought to increase the risk of ventricular arrhythmia. We investigated the relation between an abnormal QRS|T angle and mortality in a nationally representative sample of subjects without clinically evident heart disease. We studied 7,052 participants ≥40 years old in the third National Health and Nutrition Examination Survey with 12-lead electrocardiograms. Those with self-reported or electrocardiographic evidence of a previous myocardial infarction, QRS duration of ≥120 ms, or history of heart failure were excluded. Borderline and abnormal spatial QRS|T angles were defined according to gender-specific 75th and 95th percentiles of frequency distributions. All-cause (1,093 women and 1,191 men) and cardiovascular (462 women and 455 men) mortality during the 14-year period was assessed through linkage with the National Death Index. On multivariate analyses, an abnormal spatial QRS|T angle was associated with an increased hazard ratio (HR) for cardiovascular mortality in women (HR 1.82, 95% confidence interval 1.05 to 3.14) and men (HR 2.21, 95% confidence interval 1.32 to 3.68). Also, the multivariate adjusted HR for all-cause mortality associated with an abnormal QRS|T angle was 1.30 (95% confidence interval 0.95 to 1.78) for women and 1.87 (95% confidence interval 1.29 to 2.7) for men. A borderline QRS|T angle was not associated with an increased risk of all-cause or cardiovascular mortality. In conclusion, an abnormal QRS|T angle, as measured on a 12-lead electrocardiogram, was associated with an increased risk of cardiovascular and all-cause mortality in this population-based sample without known heart disease

Calcium, magnesium and potassium intake and mortality in women with heart failure: The Women\u27s Health Initiative

Although diet is thought to affect the natural history of heart failure (HF), nutrient intake in HF patients has not been well studied. Based on prior research linking high intake of Ca, Mg and K to improved cardiovascular health, we hypothesised that these nutrients would be inversely associated with mortality in people with HF. Of the 161 808 participants in the Women\u27s Health Initiative (WHI), we studied 3340 who experienced a HF hospitalisation. These participants were followed for post-hospitalisation all-cause mortality. Intake was assessed using questionnaires on food and supplement intake. Hazard ratios (HR) and 95 % CI were calculated using Cox proportional hazards models adjusted for demographics, physical function, co-morbidities and dietary covariates. Over a median of 4·6 years of follow-up, 1433 (42·9 %) of the women died. HR across quartiles of dietary Ca intake were 1·00 (referent), 0·86 (95 % CI 0·73, 1·00), 0·88 (95 % CI 0·75, 1·04) and 0·92 (95 % CI 0·76, 1·11) (P for trend = 0·63). Corresponding HR were 1·00 (referent), 0·86 (95 % CI 0·71, 1·04), 0·88 (95 % CI 0·69, 1·11) and 0·84 (95 % CI 0·63, 1·12) (P for trend = 0·29), across quartiles of dietary Mg intake, and 1·00 (referent), 1·20 (95 % CI 1·01, 1·43), 1·06 (95 % CI 0·86, 1·32) and 1·16 (95 % CI 0·90, 1·51) (P for trend = 0·35), across quartiles of dietary K intake. Results were similar when total (dietary plus supplemental) nutrient intakes were examined. In summary, among WHI participants with incident HF hospitalisation, intakes of Ca, Mg and K were not significantly associated with subsequent mortality

Reproducibility of visit-to-visit variability of blood pressure measured as part of routine clinical care

Objectives: Secondary analysis of clinical trial data suggests visit-to-visit variability (VVV) of blood pressure is strongly associated with the incidence of cardiovascular disease. Measurement of blood pressure in usual practice settings may be subject to substantial error, calling into question the value of VVV in real-world settings. Methods: We analyzed data on adults of at least 65 years of age with diagnosed hypertension who were taking antihypertensive medication from the Cohort Study of Medication Adherence among Older Adults (n = 772 with 14 or more blood pressure measurements). All blood pressure measurements, taken as part of routine outpatient care over a median of 2.8 years, were abstracted from patients’ medical charts. Results: Using each participant's first seven SBP measurements, the mean intraindividual standard deviation was 13.5 mmHg. The intraclass correlation coefficient for the standard deviation based on the first seven and second seven SBP measurements was 0.28 [95% confidence interval (CI) 0.20–0.34]. Individuals in the highest quintile of standard deviation of SBP based on their first seven measurements were more likely to be in the highest quintile of VVV using their second seven measurements (observed/expected ratio = 1.71, 95% CI 1.29–2.22). Results were similar for other metrics of VVV. The intraclass correlation coefficient was lower for DBP than SBP. Conclusion: These data suggest VVV of SBP measured in a real-world setting is not random. Future studies are needed to assess the prognostic value of VVV of SBP assessed in routine clinical practice.visit-to-visit variabilit

Population-average mediation analysis for zero-inflated count outcomes

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations.Comment: 34 pages, 2 figures, 4 tables, 49 pages of Supplemental material, 2 supplemental figure

Real-World Safety of Neurohormonal Antagonist Initiation Among Older Adults Following a Heart Failure Hospitalization

AIMS: To optimize guideline-directed medical therapy for heart failure, patients may require the initiation of multiple neurohormonal antagonists (NHAs) during and following hospitalization. The safety of this approach for older adults is not well established. METHODS AND RESULTS: We conducted an observational cohort study of 207 223 Medicare beneficiaries discharged home following a hospitalization for heart failure with reduced ejection fraction (HFrEF) (2008-2015). We performed Cox proportional hazards regression to examine the association between the count of NHAs initiated within 90 days of hospital discharge (as a time-varying exposure) and all-cause mortality, all-cause rehospitalization, and fall-related adverse events over the 90 day period following hospitalization. We calculated inverse probability-weighted hazard ratios (IPW-HRs) with 95% confidence intervals (CIs) comparing initiation of 1, 2, or 3 NHAs vs. 0. The IPW-HRs for mortality were 0.80 [95% CI (0.78-0.83)] for 1 NHA, 0.70 [95% CI (0.66-0.75)] for 2, and 0.94 [95% CI (0.83-1.06)] for 3. The IPW-HRs for readmission were 0.95 [95% CI (0.93-0.96)] for 1 NHA, 0.89 [95% CI (0.86-0.91)] for 2, and 0.96 [95% CI (0.90-1.02)] for 3. The IPW-HRs for fall-related adverse events were 1.13 [95% CI (1.10-1.15)] for 1 NHA, 1.25 [95% CI (1.21-1.30)] for 2, and 1.64 [95% CI (1.54-1.76)] for 3. CONCLUSIONS: Initiating 1-2 NHAs among older adults within 90 days of HFrEF hospitalization was associated with lower mortality and lower readmission. However, initiating 3 NHAs was not associated with reduced mortality or readmission and was associated with a significant risk for fall-related adverse events

Physical Activity and Onset of Acute Ischemic Stroke: The Stroke Onset Study

Regular physical activity is known to decrease the risk of cardiovascular disease, but the risk of ischemic stroke immediately following moderate or vigorous physical activity remains unclear. The authors evaluated the risk of acute ischemic stroke immediately following physical activity and examined whether the risk was modified by regular physical activity. In a multicenter case-crossover study, the authors interviewed 390 ischemic stroke patients (209 men, 181 women) at 3 North American hospitals between January 2001 and November 2006. Physical activity during the hour before stroke symptoms arose was compared with usual frequency of physical activity over the prior year. Of the 390 subjects, 21 (5%) reported having engaged in moderate or vigorous physical activity during the hour before ischemic stroke onset, and 6 subjects had lifted an object weighing at least 50 pounds (≥23 kg) during that hour. The rate ratio for ischemic stroke was 2.3 (95% confidence interval (CI): 1.5, 3.7; P < 0.001) for moderate or vigorous physical activity in the previous hour and 2.6 (95% CI: 1.1, 5.9; P = 0.02) for lifting 50 pounds or more. People who reported engaging in moderate or vigorous physical activity at least 3 times per week experienced a 2-fold increased risk (95% CI: 1.2, 3.3) with each bout of physical activity, as compared with a 6.8-fold risk (95% CI: 2.5, 18.8) among more sedentary subjects (P for homogeneity = 0.03)

The contributions of unhealthy lifestyle factors to apparent resistant hypertension: findings from the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study

Objectives: Unhealthy lifestyle factors may contribute to apparent treatment resistant hypertension (aTRH). We examined associations of unhealthy lifestyle factors with aTRH in individuals taking antihypertensive medications from three or more classes. Methods: Participants (n = 2602) taking three or more antihypertensive medication classes were identified from the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) study. aTRH was defined as having SBP/DBP at least 140/90 mmHg despite the use of three or more antihypertensive medication classes or the use of four or more classes to achieve blood pressure control. Lifestyle factors included obesity, physical inactivity, current smoking, heavy alcohol consumption, a low Dietary Approaches to Stop Hypertension (DASH) diet score and high sodium-to-potassium (Na/K) intake. Results: Among participants taking three or more antihypertensive medication classes, 1293 (49.7%) participants had aTRH. The prevalence of unhealthy lifestyle factors in participants with and without aTRH was 55.2 and 51.7%, respectively, for obesity, 42.2 and 40.5% for physical inactivity, 11.3 and 11.5% for current smoking, 3.1 and 4.0% for heavy alcohol consumption, 23.1 and 21.5% for low-DASH diet score, and 25.4 and 24.4% for high Na/K intake. After adjustment for age, sex, race, and geographic region of residence, none of the unhealthy lifestyle factors were associated with aTRH. The associations between each unhealthy lifestyle factor and aTRH remained nonsignificant after additional adjustment for education, income, depressive symptoms, total calorie intake, and comorbidities. Conclusions: Unhealthy lifestyle factors did not have independent associations with aTRH among individuals taking three or more antihypertensive medication classes