Impact of 2017 ACC/AHA hypertension guidelines on the prevalence of white‐coat and masked hypertension: A home blood pressure monitoring study

Dear Editor,

The 2017 American College of Cardiology/American Heart Association (ACC/AHA) hypertension guidelines modified the criteria for recognition of hypertension phenotypes, using a threshold of 130/80 mmHg for office, home, and daytime ambulatory blood pressure (BP) measures.1 When compared with the traditional criteria (TRAD‐C),2, 3, 4 that is 140/90 mmHg for office and 135/85 mmHg for home and ambulatory daytime BP, adoption of 2017 ACC/AHA criteria (ACC/AHA‐C) led to marked increases in the prevalence of sustained hypertension and sustained uncontrolled hypertension and decreases in the frequency of normotension and controlled hypertension.1, 5, 6, 7 However, the impact of ACC/AHA‐C on the prevalence of alternative relevant phenotypes,8, 9, 10 such as white‐coat hypertension, white‐coat uncontrolled hypertension, masked hypertension, and masked uncontrolled hypertension, in clinical practice is not established.

This study evaluated 5778 individuals (2939 untreated and 2839 treated with BP‐lowering medications) with age >18 years from two Brazilian cardiology centers who underwent home BP monitoring between March 2005 and February 2018. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Ethics Committee of the Oswaldo Cruz University Hospital/PROCAPE Complex, which waived the requirement for informed consent. Two clinic BP readings were taken at 60‐second intervals after 3 minutes of rest using Omron HEM‐705CP (Omron Healthcare, Kyoto, Japan) or Microlife BP3AC1‐1 (Microlife, Dunedin, FL, USA) devices, and their mean was defined as the office BP. Three home BP measurements were obtained at 60‐second intervals after 3 minutes of rest in the morning and evening for four consecutive days using the same device. The average of both morning (11.6 ± 1.1 readings) and evening (11.4 ± 1.4 readings) BP values was defined as home BP values. Definitions of hypertension phenotypes are shown in Figure 1 legend. Comparisons among the groups were performed using chi‐square test.

Figure 1.

Prevalence of hypertension phenotypes in individuals untreated (A) or treated (B) with antihypertensive medications defined by traditional* and 2017 ACC/AHA criteria**. *Untreated participants: white‐coat HT (OSBP ≥ 140 mm Hg or ODBP ≥ 90 mm Hg and HSBP < 135 mm Hg and HDBP < 85 mm Hg), masked HT (OSBP < 140 mm Hg and ODBP < 90 mm Hg and HSBP ≥ 135 mm Hg or HDBP ≥ 85 mm Hg), sustained HT (OSBP ≥ 140 mm Hg or ODBP ≥ 90 mm Hg and HSBP ≥ 135 mm Hg or HDBP ≥ 85 mm Hg), or normotension (OSBP < 140 mm Hg and ODBP < 90 mm Hg and HSBP < 135 mm Hg and HDBP < 85 mm Hg). The corresponding terms in treated patients were white‐coat uncontrolled, masked uncontrolled, sustained uncontrolled, and controlled HT, respectively. **Hypertension phenotypes were defined using the threshold of 130/80 mm Hg for office and home blood pressure measures. ACC/AHA: American College of Cardiology/American Heart Association; HT: hypertension; OSBP: office systolic blood pressure; ODBP: office diastolic blood pressure; HSBP: home systolic blood pressure; HDBP: home diastolic blood pressure

Untreated participants (n = 2939) were 48% males, had mean ± SD values of age = 51 ± 16 years, body mass index = 28.1 ± 5.2 kg/m², office SBP = 135 ± 18 mm Hg and DBP = 82 ± 11 mm Hg, and home SBP = 126 ± 14 mm Hg and DBP = 76 ± 9 mm Hg. Participants using BP‐lowering medications (n = 2839) were 44% males, had age = 58 ± 15 years, body mass index = 28.7 ± 5.1 kg/m², office SBP = 139 ± 20 mm Hg and DBP = 82 ± 12 mm Hg, and home SBP = 129 ± 16 mm Hg and DBP = 75 ± 10 mm Hg.

There were (P < 0.001) increases in the prevalence of sustained hypertension (from 22% to 42%) and white‐coat hypertension (from 19% to 30%) and decreases in the prevalence of normotension (from 52% to 24%) and masked hypertension (from 7% to 3%) in untreated participants when changing the BP thresholds used in TRAD‐C to those recommended by ACC/AHA‐C (Figure 1A). Incorporation of ACC/AHA‐C increased the frequency (P < 0.001) of sustained uncontrolled hypertension (from 28% to 48%) and white‐coat uncontrolled hypertension (from 20% to 29%) and decreased the frequency of controlled hypertension (from 45% to 19%) and masked uncontrolled hypertension (from 7% to 4%) in treated participants (Figure 1B). Furthermore, the summed prevalence of white‐coat and masked hypertension among untreated participants was higher when defined by ACC/AHA‐C as compared to TRAD‐C (34% vs. 26%; P < 0.001), and similar findings were noted for the summed prevalence of white‐coat and masked uncontrolled hypertension among treated participants (33% vs. 27%; P < 0.001).

The present data show that the detection of white‐coat phenomenon markedly increases, while the proportion of masked phenomenon decreases when applying ACC/AHA‐C instead of TRAD‐C. Furthermore, the sum of individuals with white‐coat and masked phenomena was higher when defined by ACC/AHA‐C than when defined by TRAD‐C. Given that white‐coat and masked phenomena have been associated with worse outcomes as compared to normotension or controlled hypertension,8, 9, 10 these results highlight the need of systematic out‐of‐office BP monitoring to identify diverse hypertension phenotypes in clinical practice, particularly in the light of ACC/AHA‐C.

CONFLICT OF INTEREST

None.

FUNDING INFORMATION

The study was supported by CNPq (grant 306154/2017‐0) for Dr. Nadruz.