Author + information
- Fusako Sera, MD,
- Zhezhen Jin, PhD,
- Cesare Russo, MD,
- Edward S. Lee, MD,
- Joseph E. Schwartz, PhD,
- Tatjana Rundek, MD, PhD,
- Mitchell S.V. Elkind, MD, MS,
- Shunichi Homma, MD,
- Ralph L. Sacco, MD, MS and
- Marco R. Di Tullio, MD∗ ()
- ↵∗Division of Cardiology, Columbia University, College of Physicians and Surgeons, 622 West 168th Street, New York, New York 10032
Blood pressure (BP) control in hypertensive patients is crucial for reducing the risk of heart failure development and may be particularly important in elderly subjects, who have an especially high prevalence of hypertension and risk of heart failure (1). Left ventricular (LV) global longitudinal strain (GLS) is an echocardiographic measure of LV systolic function that can be an indicator of early subclinical cardiac dysfunction, even when LV ejection fraction is normal. The association of BP control with early subclinical LV dysfunction according to GLS has not been extensively studied, and it is also unknown whether assessing BP control with ambulatory blood pressure (ABP) monitoring is superior to using office BP measurements in this regard. Therefore, we investigated the association of BP control with GLS by using ABP and office BP criteria in a community-based, predominantly elderly cohort with normal LV ejection fraction.
The study cohort consisted of 394 treated hypertensive patients (mean age 72 ± 9 years; 63% women) with LV ejection fraction ≥50% from the CABL (Cardiac Abnormalities and Brain Lesion) study. The patients underwent transthoracic echocardiography and ABP monitoring. Uncontrolled office BP was defined as office systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg; uncontrolled 24-h ABP as mean 24-h SBP ≥130 mm Hg and/or DBP ≥80 mm Hg; uncontrolled daytime ABP as mean daytime SBP ≥135 mm Hg and/or DBP ≥85 mm Hg; and uncontrolled night-time ABP as mean night-time SBP ≥120 mm Hg and/or DBP ≥70 mm Hg (2).
Speckle-tracking analysis was performed on digital echocardiographic images by using commercially available software (QLAB Advanced Quantification Software version 8.1, Philips, Andover, Massachusetts). The GLS was calculated by averaging the negative peak of longitudinal strain of 12 LV segments from the apical 4- and 2-chamber views. Abnormal GLS was defined as a GLS more than –14.7%, which is the 95th percentile of the GLS distribution in the healthy normotensive subjects from the CABL cohort (3).
Seventy-seven subjects (19.5%) had abnormal GLS. Office BP was uncontrolled in 188 subjects (47.7%), and 24-h ABP was uncontrolled in 162 (41.1%). Concordant classification of BP control between office BP and 24-h ABP was identified only in 230 subjects (58.4%; kappa = 0.16; 95% confidence interval [CI]: 0.06 to 0.26). Uncontrolled daytime and night-time ABP were identified in 36.6% and 53.0% of participants, respectively.
In univariable logistic regression analyses, uncontrolled 24-h ABP was significantly associated with abnormal GLS (odds ratio: 2.95; 95% CI: 1.76 to 4.93; p < 0.0001), whereas uncontrolled office BP was not (odds ratio: 1.41; 95% CI: 0.85 to 2.32; p = 0.18). After adjustment for age, diabetes mellitus, coronary artery disease, and LV mass index, uncontrolled 24-h ABP remained significantly associated with abnormal GLS (Figure 1). A significant association with abnormal GLS was also found by using either daytime or night-time criteria (Figure 1).
We show, for the first time, the superiority of ABP control over office BP control for the risk stratification of treated hypertensive subjects for the presence of subclinical LV systolic dysfunction. In a hypertensive animal model, impairment of GLS occurred in parallel with the accumulation of fibrosis induced by pressure overload in the LV subendocardium in the early stage of hypertensive heart failure (4). Therefore, we speculate that consistent reduction of LV pressure overload throughout the 24 h by antihypertensive medications might be important in delaying the progression of LV systolic dysfunction and that ABP control may be a better indicator of the effective reduction of LV pressure overload than office BP control. Of note, inadequate ABP control was more frequent at night than during the day in this cohort, further underlining how office BP does not provide an adequate representation of BP values in a critical period of the day.
Evaluating BP control by use of ABP monitoring, but not by office BP, may identify patients with hypertension at higher risk of early LV systolic dysfunction. Whether achieving BP control according to ABP criteria may help decrease the risk of developing subclinical LV systolic dysfunction, and possibly slow its progression to clinical heart failure, is a hypothesis that deserves further investigation.
Please note: This study was supported by grants from the National Institute of Neurological Disorders and Stroke (R01 NS36286 and R37 NS29993). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
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