Using out-of-office blood pressure measurements in established cardiovascular risk scores: a secondary analysis of data from two blood pressure monitoring studies

Abstract

Item Type Article Authors Stevens, S.L.; Stevens, R.J.; de Leeuw, P.; Kroon, A.A.; Greenfield, S.; Mohammed, Mohammed A.; Gill, P.; Verberk, W.J.; McManus, R.J. Citation Stevens SL, Stevens RJ, de Leeuw P et al (2019) Using outof-office blood pressure measurements in established cardiovascular risk scores: implications for practice. British Journal of General Practice. 69(683): e381-e388. Rights AbstractBackground: Blood pressure (BP) measurement is increasingly carried out through home or ambulatory monitoring, yet existing cardiovascular risk scores were developed for use with measurements obtained in clinic.Aim: To describe differences in cardiovascular risk estimates obtained using ambulatory or home BP measurements instead of clinic readings.Design and setting: Secondary analysis of data from adults aged 30-84 without prior history of cardiovascular disease (CVD) in two BP monitoring studies (BP-Eth and HOMERUS). Method:The primary comparison was Framingham risk calculated using BP measured as in the Framingham study or daytime ambulatory BP measurements. The QRISK2 and SCORE risk equations were also studied. Statistical and clinical significance were determined using the Wilcoxon signedrank test and scatter plots respectively. Results:In 442 BP-Eth patients (mean age = 58 years, 50% female) the median absolute difference in 10-year Framingham cardiovascular risk calculated using BP measured as in the Framingham study or daytime ambulatory BP measurements was 1.84% (interquartile range 0.65 to 3.63, p=0.67). Only 31/ 442 (7.0%) of patients were reclassified across the 10% risk treatment threshold. In 165 HOMERUS patients (mean age = 56 years, 46% female) the median difference in 10-year risk was 2.76% (IQR 1.19 to 6.39, p<0.001) and only 8/165 (4.8%) of patient were reclassified.Conclusion: Estimates of cardiovascular risk are similar when calculated using BP measurements obtained as in the risk score derivation study or through ambulatory monitoring. Further research is required to determine if differences in estimated risk would meaningfully influence risk score accuracy. How this fits in:Out-of-office blood pressure (BP) measurement is increasingly common but cardiovascular risk scores were developed using clinic BP measurements. It is unclear how estimates of cardiovascular risk may be affected by the use of out-of-office measurements in risk prediction algorithms. We have shown that differences in risk are generally small and few patients are reclassified across treatment thresholds when using different BP measurements. Extra care on the part of clinicians may be warranted in subgroups with large BP differences or those with risk estimates close to risk thresholds.

Higher Framingham Risk Scores are associated with greater loss of brain volume over time in multiple sclerosis

“…Nonetheless, our findings were consistent when we limited the sample to whites, and when we limited analyses to those with relapsing remitting MS. We assessed blood pressure based on one measurement but usual blood pressure may be estimated more accurately by averaging several measurements. Nonetheless, 24 hour ambulatory blood pressure monitoring has little effect on the predictive accuracy of the FRS (Bell et al, 2014;Lay--Flurrie et al, 2019). Hyperlipidemia was not used to calculate our primary exposure of interest (FRS) and was assessed based on self-report and medical records review rather than lipid testing.…”

Clinical applications for out-of-office blood pressure monitoring

“…47 Recently, another study also showed that using BP measurements obtained through ABPM or HBPM instead of OBPM may have little effect on CVD risk estimates obtained from the Framingham, QRISK2 (risk of developing a heart attack or stroke over the next 10 years), or SCORE (Systematic COronary Risk Evaluation) risk equations. 48 Therefore, current cardiovascular risk assessment systems, including China-PAR (Prediction for Atherosclerotic CVD [ASCVD] Risk in China), 49 European SCORE, 50 ASCVD-PCE (Pooled Cohorts Equations) of the USA, 51 the Q risk score (QRISK) model of Great Britain, 52 and the Framingham Risk Score, 53 include only clinic BP in the model. However, all of these cardiovascular risk assessment systems were developed in the general population.…”

The potential for overdiagnosis and underdiagnosis because of blood pressure variability: a comparison of the 2017 ACC/AHA, 2018 ESC/ESH and 2019 NICE hypertension guidelines

“…Our simulation did not investigate the possibility of discordant results between different types of measurement, such as high office BP and normal ambulatory BP or home BP in people with a true SBP <140 mmHg (‘white-coat hypertension’) or normal office BP and high ambulatory BP or home BP in people with true SBP at least 140 mmHg or abnormal BP response (including ‘masked hypertension’, ‘nocturnal hypertension’ and an exaggerated blood pressure response to exercise), nor the possibility that BP variation itself provides important prognostic information [ 41 ]. However, we note that when using a risk-based approach rather than focusing on blood pressure alone, the addition of out-of-office measurements (including night time BP and measures of variability) [ 42 , 43 ] or indeed repeated office measurements [ 44 , 45 ] appear to have minimal impact on clinical decision-making. Finally, we did not explore psychosocial consequences of over diagnosis and underdiagnosis, clinical consequences of overtreatment and undertreatment and health resource use/cost consequences.…”