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Revisado por pares
DAYTIME SYSTOLIC BLOOD PRESSURE LOAD AND PREVIOUS STROKE PREDICT CARDIOVASCULAR EVENTS IN TREATED OCTOGENARIANS WITH HYPERTENSION
2010; Wiley; Volume: 58; Issue: 11 Linguagem: Inglês
10.1111/j.1532-5415.2010.03106.x
ISSN1532-5415
AutoresSmalyanna Sgren da Costa Andrade, João Batista Serro‐Azul, Amit Nussbacher, D Giorgi, Humberto Pierri, Otávio Gebara, Maurı́cio Wajngarten,
Tópico(s)Heart Rate Variability and Autonomic Control
ResumoTo the Editor: Although very old people are underrepresented in large clinical trials of hypertension, variables obtained from ambulatory blood pressure monitoring (ABPM) may be better associated with cardiovascular events and damage to target organs than casual blood pressure (BP) measurement.1,2 The purpose of this study was to evaluate whether ABPM variables could identify the risk of cardiovascular events in very old individuals being treated for hypertension. Patients were selected from the Outpatient Geriatric Cardiology Clinic of the Heart Institute of the University of São Paulo, São Paulo, Brazil. Selection criteria were aged 80 and older, hypertension as the main reason for treatment, systolic BP (SBP) less than 140 mmHg, and diastolic BP (DBP) less than 90 mmHg. Exclusion criteria included the presence of atrial fibrillation, significant valvular heart disease, dialysis, advanced dementia, and Parkinson's disease. Patients were seen at the clinic every 6 months during the follow-up period of 23.0±5.6 months. A physician measured BP in the office with the subject in a seated position after 10 minutes of rest. ABPM was conducted using the Spacelabs 90207 monitor (Spacelabs, Redmond, WA). BP was obtained every 10 minutes between 6:00 a.m. and 11:00 p.m. (waking period) and every 20 minutes between 11:00 p.m. and 6:00 a.m. (sleeping period). The systolic and diastolic loads, defined as the average percentages above 135 and 85 mmHg, respectively, during the waking period and as the percentage of measures over 120 and 80 mmHg, respectively, during the sleeping period were evaluated. Variables associated with risk of events according to univariate analysis were entered into a Cox model regression analysis (Figure 1). Survival curves based on multivariate Cox regression. Model with subjects with daytime systolic blood pressure load of 24.5% or greater. Patients without previous stroke in solid line and with previous stroke in dotted line. One hundred twenty-six people aged 80 and older (83.8±3.4, 62.7% women) with stable antihypertensive drug treatment for at least 3 months were included. Patients were divided into two groups according to the occurrence of cardiovascular events. During follow-up, 12 cardiovascular events occurred: six coronary events (6 patients with acute coronary syndrome, 1 of which was fatal) and six of cerebral origin (4 patients with stroke and 2 with transient ischemic attack). The prevalence of cardiovascular risk factors, comorbidities, and antihypertensive and cardiovascular medications was similar in both groups. The group with events had a significantly more-frequent history of prior stroke (33.3% vs 7.0%, P=.02). There was no difference in office BP between the groups. The following ABPM variables were higher in the group with events: daytime SBP (138.0±13.4 vs 126.0±13.2 mmHg; P=.003), nighttime SBP (133.6±19.8 vs 121.7±16.8 mmHg, P=.02), daytime SBP load (44.2±24.1 vs 20.6±22.6%; P=.009), and nighttime SBP load (71.6±30.5 vs 47.2±37.1%; P=.047). The only two variables that were independently associated with the occurrence of cardiovascular events were a history of stroke (hazard ratio (HR)=15.0, 95% confidence interval (CI)=3.4–65.8; P<.001) and daytime SBP load of 24.5% or greater (HR=15.0, 95% CI=3.1–73.3; P=.001). Daytime SBP load of 24.5% or greater yielded 83% sensitivity and 68% specificity for prediction of events, a negative predictive value of 98%, and an accuracy of 74.6%. Treatment recommendations for hypertension in very older people are based on the results of studies of younger individuals with hypertension or analysis of subgroups. Only recently, the Hypertension in the Very Elderly Trial3 provided evidence of the benefits of treatment of hypertension in octogenarians. Various studies demonstrated a relationship between parameters from ABPM and cardiovascular risk in older people, yet they involved relatively young individuals.4–9 In this investigation, there were 12 cardiovascular events, corresponding to 9.5% of the sample studied. Daytime SBP load was an independent marker of cardiovascular events in octogenarians with hypertension in treatment. The only other independent marker was a history of prior stroke. Especially for patients with previous stroke, daytime SBP load increased substantially the risk of events in an exponential manner. The great prognostic effect of high daytime SBP load in these very old people could represent the greater BP variability that is so common in this age group that results in greater oscillations and hampers adequate BP control during usual daily activities. In conclusion, for octogenarians being treated for hypertension, especially those with previous stroke, ABPM can help to identify those at greater cardiovascular risk for future events. A daytime systolic load of 24.5% or greater is an independent and strong predictor of events, entailing an almost 15 times greater risk. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. This study was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (Grant 02/13688-6). Author Contributions: Solange de Sousa Andrade: acquisition of subjects and data, analysis and interpretation of data, and preparation of manuscript. João Batista Serro Azul and Otavio Celso Eluf Gebara: analysis and interpretation of data. Amit Nussbacher and Humbrto Pierri: preparation of manuscript. Dante Marcelo Artigas Giorgi: interpretation of data. Mauricio Wajngarten: analysis and interpretation of data, and preparation of manuscript.
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