White-coat hypertension, as defined by ambulatory blood pressure monitoring, and subclinical cardiac organ damage: a meta-analysis

White-coat hypertension during coronary computed tomography angiography is associated with higher coronary atherosclerotic burden

INTRODUCTION

White-coat hypertension (WCH) is a prevalent entity, which has been associated with an increased cardiovascular risk.

AIM

Assess whether WCH is associated with a higher coronary atherosclerotic burden, evaluated by coronary computed tomography angiography (CCTA) and coronary artery calcium (CAC) scoring.

METHODS

A total of 1362 patients who performed CCTA and simultaneous CAC for the assessment of coronary artery disease (CAD) were prospectively enrolled in a single-center registry and divided into three groups: (A) patients with normal blood pressure (BP) (n=386); (B) patients with WCH (n=174; without a history of hypertension or antihypertensive medication, but with systolic BP ≥140 and/or diastolic BP ≥90 mmHg before examination acquisition); and (C) patients with hypertension (n=802). The following coronary atherosclerotic markers were evaluated: CAC above the 50th percentile (CAC>p50), prevalence of CAD (any plaque), and obstructive CAD (plaque with>50% stenosis).

RESULTS

Patients with WCH had a higher coronary atherosclerotic burden compared with patients with normal BP for all markers (30.5 vs. 19.4%, P=0.004 for CAC>p50; 50.6 vs. 36.8%, P=0.002 for CAD, any plaque; and 13.8 vs. 8.3%, P=0.045 for obstructive CAD). On multivariate analysis, WCH was an independent predictor of a CAC>p50 [odds ratio (OR) 1.563, 95% confidence interval 1.018-2.400, P=0.041], but not of the presence of CAD (any plaque) (OR 1.335, P=0.169) or obstructive CAD (OR 1.376, P=0.301).

CONCLUSION

In this registry of patients, WCH was an independent predictor of a CAC above the p50. It was also associated with higher other markers of coronary atherosclerotic burden, such as the presence of CAD on CCTA, compared with patients with normal BP.

ABPM Induced Alarm Reaction: A Possible Cause of Overestimation of Daytime Blood Pressure Values Reduced By Treatment with Beta-Blockers

INTRODUCTION

Alarm reaction to clinical blood pressure (BP) measurement, defined white-coat effect (WCE), can cause overestimation of true BP values.

AIM

To assess whether ambulatory blood pressure monitoring (ABPM) can similarly affect BP values during the initial hours of recording.

METHODS

In 420 ABPMs selected for a first systolic BP (SBP) reading at least 10 mmHg higher than the mean daytime SBP, we calculated mean diurnal and 24 h SBP with and without the exclusion of the two first hours of recording defined as the WCE window (WCEw). We also calculated the magnitude and duration of WCE. These analyses were also performed separately in patients off anti-hypertensive treatment (n = 156), and on treatment with and without the inclusion of beta-blockers (respectively n = 113 and 151).

RESULTS

Exclusion of WCEw period reduced mean diurnal and 24 h SBP respectively from 135 ± 0.5 to 133 ± 0.5 (p < 0.01) and from 131 ± 0.5 to 130 ± 0.5 (p < 0.02). As a result the percentage of patients diagnosed as having diurnal or 24 h hypertension was reduced respectively from 48 to 40 % and from 52 to 47 %. The magnitude of WCEw was similar in both genders but the duration was longer in females (66 ± 2 vs. 56 ± 2 min, p < 0.01). Treatment with beta-blockers was associated with a shorter duration of WCE in both genders but this effect was statistically significant only in males.

CONCLUSIONS

In some patients ABPM is not free from WCE. WCE may affect the overall estimation of BP profile and is longer but less blunted by beta-blockers in females than in males.

Is It Daily, Monthly, or Yearly Blood Pressure Variability that Enhances Cardiovascular Risk?

Variability is a phenomenon common to most biological processes that we can measure and is a particular feature of blood pressure (BP). Variability causes concern for many physicians regarding its clinical meaning and potential impact on cardiovascular risk. In this review, we assess the role of different time periods of blood pressure variability (BPV) in cardiovascular risk stratification. We review the indices of BPV derived from ambulatory blood pressure measurement (ABPM), home blood pressure measurement (HBPM), or at the clinic setting with the intention of providing a clear message for clinical practice. BPV, either derived from ABPM or HBPM, does not consistently augment cardiovascular risk prediction over and beyond that of average BP, particularly in low-risk individuals. That said, it would seem that certain medications such as calcium channel blockers may have a beneficial effect on visit-to-visit BPV and perhaps reduce the associated cardiovascular risk. This highlights the benefits in using combination therapy which might couple a number of therapeutic benefits such as the reductions of mean blood pressure and BPV. Overall, we should remain aware that the average BP level remains the main modifiable risk factor derived from BP measurements and continue to improve the control of hypertension and adverse health outcomes.

Influence of White-Coat Hypertension on Left Ventricular Deformation 2- and 3-Dimensional Speckle Tracking Study

We sought to compare left ventricular deformation in subjects with white-coat hypertension to normotensive and sustained hypertensive patients. This cross-sectional study included 139 untreated subjects who underwent 24-hour ambulatory blood pressure monitoring and completed 2- and 3-dimensional examination. Two-dimensional left ventricular multilayer strain analysis was also performed. White-coat hypertension was diagnosed if clinical blood pressure was elevated and 24-hour blood pressure was normal. Our results showed that left ventricular longitudinal and circumferential strains gradually decreased from normotensive controls across subjects with white-coat hypertension to sustained hypertensive group. Two- and 3-dimensional left ventricular radial strain, as well as 3-dimensional area strain, was not different between groups. Two-dimensional left ventricular longitudinal and circumferential strains of subendocardial and mid-myocardial layers gradually decreased from normotensive control to sustained hypertensive group. Longitudinal and circumferential strains of subepicardial layer did not differ between the observed groups. We concluded that white-coat hypertension significantly affects left ventricular deformation assessed by 2-dimensional traditional strain, multilayer strain, and 3-dimensional strain.

Blood Pressure Out of the Office: Its Time Has Finally Come

The diagnosis of hypertension includes measurement of blood pressure out of the office by either 24-hour ambulatory monitoring or home blood pressure monitoring. These methods have led to recognition of "white coat hypertension" (WCH) and "masked hypertension" (MH). Research in the 1930s first demonstrated that blood pressures in the office were often far different from those out of the office, at a time when there was no effective treatment. International attention was focused on another imminent world war and a highly controversial election in the United States. Hypertension was not a priority for concern. From the 1950s onward: (i) epidemiology linked hypertension to risk of cardiovascular disease, (ii) effective and safe drugs for treatment of hypertension appeared, (iii) randomized clinical trials demonstrated that drug treatment of hypertension is highly effective for prevention of cardiovascular disease, and (iv) advances in technology led to development of small, portable devices for recording blood pressure noninvasively at home or during usual activities. Accurate measurement of blood pressure in "real life" is now necessary and feasible for appropriate diagnosis and assessment of treatment. Out-of-office blood pressure measurement is emerging as the standard of care for hypertension.

Myocardial Performance Index in Childhood Onset Essential Hypertension and White Coat Hypertension

BACKGROUND

As a global measure of ventricular systolic and diastolic function, the myocardial performance index (MPI) can be an early indicator of hypertensive cardiomyopathy in children with essential hypertension (EH).

METHODS

Children with untreated newly diagnosed EH and white coat hypertension (WCH) by a 24-hour ambulatory blood pressure monitoring (ABPM), both groups without any identifiable etiology for the hypertension, were enrolled for the study. Echocardiograms and vascular ultrasounds for carotid artery intimal medial thickness were performed on all children prior to therapy. Diastolic function (peak E and A velocities, E/A ratio, isovolumic relaxation time, and deceleration times) and MPI were evaluated by simultaneous transmitral and transaortic spectral Doppler flow velocities. Systolic function was evaluated by shortening fraction and ejection fraction.

RESULTS

A cohort of 66 children (24 with EH, 42 with WCH, males 61%, median age of 13 years, range 10-17 years) were enrolled in the study. The demographic, anthropometric, laboratory tests, vascular ultrasound, and conventional echocardiographic parameters were similar between the 2 groups. There was a very small difference in MPI between the EH and WCH children (0.28 SD: 0.07 vs. 0.31 SD: 0.08, P = 0.045). However, in EH children, MPI increased by 0.14 units for every 10 unit increase in mean ABPM systolic BP (95% confidence interval: 0.03-0.25).

CONCLUSIONS

We found the increasing MPI was associated with increasing 24-hour mean systolic BP in children with EH. Therefore, MPI may have utility as a single, quick, noninvasive method of detection and tracking of subclinical hypertensive heart disease.

Adverse prognostic value of persistent office blood pressure elevation in white coat hypertension

Stratification of cardiovascular risk is of fundamental importance in white coat hypertension (WCH) to identify individuals in need of closer follow-up and perhaps antihypertensive drug treatment. In subjects representative of the general population of Monza (Italy), the risk of cardiovascular and all-cause mortality was assessed >16 years in stable and unstable WCH individuals, that is, those in whom ambulatory blood pressure (BP) normality was associated with a persistent or nonpersistent office BP elevation at 2 consecutive visits, respectively. Data were compared with those from an entirely normotensive group, that is, ambulatory and persistent office BP normality. Compared with the normotensive group, the risk of cardiovascular and all-cause death was not significantly different in unstable WCH, whereas in stable WCH the risk was increased also when data were adjusted for baseline confounders, including ambulatory BP (hazard ratio, 16; P=0.001 for cardiovascular death and 1.92; P=0.02 for all-cause death). At a multivariable analysis, office BP was among the factors independently predicting death, and results were superimposable with use of Monza population-derived and guidelines-derived cutoff values for ambulatory BP normality (125/79 and 130/80 mm Hg, respectively). Thus, only when office BP is persistently elevated does WCH reflect the existence of an abnormal long-term mortality risk. This means that in WCH office BP is prognostically relevant and that repeated collection of its values is clinically important to better define patient risk.

White coat hypertension: improving the patient-health care practitioner relationship

White coat hypertension is characterized by the variability of a patient’s blood pressure measurements between the physician’s office and the patient’s home environment. A patient with white coat hypertension has high blood pressure levels in the physician’s office and normal blood pressure levels in their typical environment. This condition is likely caused by the patient’s anxiety within the physician’s office and in the presence of the physician. Research has shown that improving the relationship between a patient and their health care provider can decrease the patient’s anxiety, with the implication of decreasing the patient’s likelihood of demonstrating white coat hypertension. This review provides an overview of the previous literature regarding white coat hypertension, its prevalence, and the consequences for those who develop persistent hypertension. Furthermore, this review discusses the implications of improving patient and health care provider interactions through effective communication, empathy, and trust, as well as the implications for future research studies in improving the patient and health care provider’s relationship.