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Is the use of ABPM justified in patients on 1 or 2 antihypertensive medications?
International Journal of Cardiology 125 (2008) 118 – 119 www.elsevier.com/locate/ijcard
Letter to the Editor
Is the use of ABPM justified in patients on 1 or 2 antihypertensive medications? Gaurav Mathur a,⁎, Rachana Prasad b , Anne Robinson b , Erwin Rodrigues b , Peter Wong b a
University of Hull, Department of Academic Cardiology, Castle Hill Hospital, Castle Hill Road, Cottingham, East Riding of Yorkshire, UK b Aintree Cardiac Centre, University Hospital Aintree, Liverpool, UK Received 24 November 2006; accepted 1 January 2007 Available online 17 April 2007
Abstract We studied the utility of ABPM in patients with elevated clinic BP on 1–2 antihypertensive medications (group B, N = 117), compared with those on no medications (group A, N = 76) and on ≥ 3 medications (group C, N = 110). 35% of patients in group B had adequately controlled 24-h BP based on ABPM, compared with 22.4% in group A (P = 0.06) and 19.1% in group C (P = 0.007). Antihypertensive treatment was not escalated in patients with adequately controlled BP. This suggests that ABPM has an important role in therapeutic decisionmaking for patients on 1–2 antihypertensive medications. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Hypertension; Ambulatory blood pressure monitoring; Antihypertensive medications; Blood pressure control; White coat hypertension
1. Introduction Ambulatory blood pressure monitoring (ABPM) is a better predictor of cardiovascular events than clinic BP in subjects not on antihypertensive treatment [1], treated hypertensive subjects [2,3] and patients with resistant hypertension (clinic BP ≥ 140/90 mm Hg despite treatment with 3 or more antihypertensive agents) [2]. Though the value of ABPM in the evaluation of suspected white coat hypertension and resistant hypertension is well-established, few studies have focused on patients with elevated clinic BP on 1–2 antihypertensive medications. A considerable proportion of treated hypertensive patients have inadequate BP control based on clinic BP readings [4]. Use of ABPM shows adequate BP control in a larger proportion of treated hypertensive subjects, leading to less intensive drug treatment and fewer clinic visits [5,6]. We studied the impact of ABPM on assessment of BP control and adjustment of medications in patients with elevated clinic BP ⁎ Corresponding author. Tel.: +44 7782215492. E-mail address: [email protected] (G. Mathur). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.01.014
Table 1 Clinical characteristics Clinical characteristics
Group A (N = 76)
Group B (N = 117)
Group C (N = 110)
Clinic systolic BP, mm Hg† 154 (18.6)
160.5 (20.3)
Clinic diastolic BP, mm Hg† Average 24-h systolic BP, mm Hg† Average 24-h Diastolic BP, mm Hg† Age†
90.1 (12)
89 (9.6)
138.1 (13.2)
135.7 (15.1)
80.2 (8.5)
77.1 (10.5)
50.4 (15.1)⁎
61.1 (14.7)
Men Smokers Diabetes Stroke/TIA Ischemic heart disease Hyperlipidemia Peripheral vascular disease
39 12 4 3 5⁎ 15 0
57 16 7 3 28 38 2
169.2 (22.3) 92.7 (12.2) 143.3 (17.3) 77.8 (10.4) 64.5 (13.2) 53 15 17⁎ 10⁎ 28 49 6
⁎ Denotes significant difference compared with Group B. Data are presented as mean (S.D.).
†
G. Mathur et al. / International Journal of Cardiology 125 (2008) 118–119 Table 2 Blood pressure control based on ABPM
4. Discussion Groups
BP based on ABPM Total
Controlled Uncontrolled
119
A
B
C
17 59 76
41 76 117
21 89 110
on 1–2 antihypertensive medications, compared with those on no medications or on ≥3 antihypertensive medications. 2. Methods ABPM results and clinic letters prior and subsequent to ABPM were analyzed for 303 consecutive patients who underwent ABPM using Delmar Reynolds equipment at University Hospital Aintree from July 2004 to December 2004. Data was collected regarding cardiovascular risk factors; clinic BP and medications prior to ABPM; changes in treatment following ABPM; and average 24-h BP recordings. Patients were classified into 3 groups based on the number of antihypertensive medications at the time of ABPM analysis: Group A, on no antihypertensive medications; Group B, on 1–2 antihypertensives; and Group C, on 3 or more antihypertensives. Patients were considered to have uncontrolled hypertension if the average systolic and/or diastolic 24-h BP readings were ≥ 130 mm Hg and 80 mm Hg, respectively. Data was analyzed using SPSS (Version 11.5). Categorical variables were compared by chisquare test, and differences were considered significant if the P value was b0.05. 3. Results The mean age of patients was 59.6 years (S.D. 15.3; Range 20–92 years). All had elevated clinic BP readings (systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg) prior to ABPM. Overall, patients in group A were younger and had less incidence of ischemic heart disease than groups B or C. Patients in group C had higher incidence of diabetes and stroke than group B (Table 1). As shown in Table 2, 35% of patients in group B had adequately controlled BP based on ABPM, compared with 19.1% in group C (significant, P = 0.007) and 22.4% in group A (P = 0.06). In all groups, antihypertensive treatment was not escalated for patients with adequately controlled BP.
Dose adjustments in patients on 1 or 2 antihypertensive agents are frequently based on clinic BP readings. However, ABPM generally reveals better BP control than suggested by clinic readings, and it is also a better predictor of cardiovascular events. We found that a considerable proportion of patients with elevated clinic BP on 1–2 antihypertensives had good BP control based on ABPM readings, so that further treatment escalation was not required. The reasons for the difference in BP control between groups B and C are not well understood. It is possible that some of the patients in Group B actually had undetected white coat hypertension, and a trial of withdrawal of treatment with BP monitoring might be feasible [7]. Also, the higher incidence of diabetes and stroke in group C suggests that these patients have more comorbidities, which would impact on their BP control. 5. Conclusion ABPM is useful to prevent unnecessary escalation of treatment in a significant proportion of patients on 1–2 antihypertensive medications. References [1] Verdecchia P. Prognostic value of ambulatory blood pressure: current evidence and clinical implications. Hypertension Mar 2000;35(3):844–51. [2] Pierdomenico SD, Lapenna D, Bucci A, et al. Cardiovascular outcome in treated hypertensive patients with responder, masked, false resistant, and true resistant hypertension. Am J Hypertens Nov 2005;18(11):1422–8. [3] Clement DL, De Buyzere ML, De Bacquer DA, et al. Prognostic value of ambulatory blood-pressure recordings in patients with treated hypertension. N Engl J Med Jun 12 2003;348(24):2407–15. [4] Wolf-Maier K, Cooper RS, Kramer H, et al. Hypertension Treatment and Control in Five European Countries, Canada, and the United States. Hypertension Jan 1 2004;43(1):10–7. [5] Staessen JA, Byttebier G, Buntinx F, Celis H, O'Brien ET, Fagard R. Antihypertensive treatment based on conventional or ambulatory blood pressure measurement. A randomized controlled trial. Ambulatory Blood Pressure Monitoring and Treatment of Hypertension Investigators. JAMA Oct 1 1997;278(13):1065–72. [6] Lorgelly P, Siatis I, Brooks A, Slinn B, Millar-Craig MW, Donnelly R, et al. Is ambulatory blood pressure monitoring cost-effective in the routine surveillance of treated hypertensive patients in primary care? Br J Gen Pract Oct 2003;53(495):794–6. [7] Myers MG, Reeves RA, Oh PI, Joyner CD. Overtreatment of hypertension in the community? Am J Hypertens May 1996;9(5):419–25.
Letter to the Editor
Is the use of ABPM justified in patients on 1 or 2 antihypertensive medications? Gaurav Mathur a,⁎, Rachana Prasad b , Anne Robinson b , Erwin Rodrigues b , Peter Wong b a
University of Hull, Department of Academic Cardiology, Castle Hill Hospital, Castle Hill Road, Cottingham, East Riding of Yorkshire, UK b Aintree Cardiac Centre, University Hospital Aintree, Liverpool, UK Received 24 November 2006; accepted 1 January 2007 Available online 17 April 2007
Abstract We studied the utility of ABPM in patients with elevated clinic BP on 1–2 antihypertensive medications (group B, N = 117), compared with those on no medications (group A, N = 76) and on ≥ 3 medications (group C, N = 110). 35% of patients in group B had adequately controlled 24-h BP based on ABPM, compared with 22.4% in group A (P = 0.06) and 19.1% in group C (P = 0.007). Antihypertensive treatment was not escalated in patients with adequately controlled BP. This suggests that ABPM has an important role in therapeutic decisionmaking for patients on 1–2 antihypertensive medications. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Hypertension; Ambulatory blood pressure monitoring; Antihypertensive medications; Blood pressure control; White coat hypertension
1. Introduction Ambulatory blood pressure monitoring (ABPM) is a better predictor of cardiovascular events than clinic BP in subjects not on antihypertensive treatment [1], treated hypertensive subjects [2,3] and patients with resistant hypertension (clinic BP ≥ 140/90 mm Hg despite treatment with 3 or more antihypertensive agents) [2]. Though the value of ABPM in the evaluation of suspected white coat hypertension and resistant hypertension is well-established, few studies have focused on patients with elevated clinic BP on 1–2 antihypertensive medications. A considerable proportion of treated hypertensive patients have inadequate BP control based on clinic BP readings [4]. Use of ABPM shows adequate BP control in a larger proportion of treated hypertensive subjects, leading to less intensive drug treatment and fewer clinic visits [5,6]. We studied the impact of ABPM on assessment of BP control and adjustment of medications in patients with elevated clinic BP ⁎ Corresponding author. Tel.: +44 7782215492. E-mail address: [email protected] (G. Mathur). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.01.014
Table 1 Clinical characteristics Clinical characteristics
Group A (N = 76)
Group B (N = 117)
Group C (N = 110)
Clinic systolic BP, mm Hg† 154 (18.6)
160.5 (20.3)
Clinic diastolic BP, mm Hg† Average 24-h systolic BP, mm Hg† Average 24-h Diastolic BP, mm Hg† Age†
90.1 (12)
89 (9.6)
138.1 (13.2)
135.7 (15.1)
80.2 (8.5)
77.1 (10.5)
50.4 (15.1)⁎
61.1 (14.7)
Men Smokers Diabetes Stroke/TIA Ischemic heart disease Hyperlipidemia Peripheral vascular disease
39 12 4 3 5⁎ 15 0
57 16 7 3 28 38 2
169.2 (22.3) 92.7 (12.2) 143.3 (17.3) 77.8 (10.4) 64.5 (13.2) 53 15 17⁎ 10⁎ 28 49 6
⁎ Denotes significant difference compared with Group B. Data are presented as mean (S.D.).
†
G. Mathur et al. / International Journal of Cardiology 125 (2008) 118–119 Table 2 Blood pressure control based on ABPM
4. Discussion Groups
BP based on ABPM Total
Controlled Uncontrolled
119
A
B
C
17 59 76
41 76 117
21 89 110
on 1–2 antihypertensive medications, compared with those on no medications or on ≥3 antihypertensive medications. 2. Methods ABPM results and clinic letters prior and subsequent to ABPM were analyzed for 303 consecutive patients who underwent ABPM using Delmar Reynolds equipment at University Hospital Aintree from July 2004 to December 2004. Data was collected regarding cardiovascular risk factors; clinic BP and medications prior to ABPM; changes in treatment following ABPM; and average 24-h BP recordings. Patients were classified into 3 groups based on the number of antihypertensive medications at the time of ABPM analysis: Group A, on no antihypertensive medications; Group B, on 1–2 antihypertensives; and Group C, on 3 or more antihypertensives. Patients were considered to have uncontrolled hypertension if the average systolic and/or diastolic 24-h BP readings were ≥ 130 mm Hg and 80 mm Hg, respectively. Data was analyzed using SPSS (Version 11.5). Categorical variables were compared by chisquare test, and differences were considered significant if the P value was b0.05. 3. Results The mean age of patients was 59.6 years (S.D. 15.3; Range 20–92 years). All had elevated clinic BP readings (systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg) prior to ABPM. Overall, patients in group A were younger and had less incidence of ischemic heart disease than groups B or C. Patients in group C had higher incidence of diabetes and stroke than group B (Table 1). As shown in Table 2, 35% of patients in group B had adequately controlled BP based on ABPM, compared with 19.1% in group C (significant, P = 0.007) and 22.4% in group A (P = 0.06). In all groups, antihypertensive treatment was not escalated for patients with adequately controlled BP.
Dose adjustments in patients on 1 or 2 antihypertensive agents are frequently based on clinic BP readings. However, ABPM generally reveals better BP control than suggested by clinic readings, and it is also a better predictor of cardiovascular events. We found that a considerable proportion of patients with elevated clinic BP on 1–2 antihypertensives had good BP control based on ABPM readings, so that further treatment escalation was not required. The reasons for the difference in BP control between groups B and C are not well understood. It is possible that some of the patients in Group B actually had undetected white coat hypertension, and a trial of withdrawal of treatment with BP monitoring might be feasible [7]. Also, the higher incidence of diabetes and stroke in group C suggests that these patients have more comorbidities, which would impact on their BP control. 5. Conclusion ABPM is useful to prevent unnecessary escalation of treatment in a significant proportion of patients on 1–2 antihypertensive medications. References [1] Verdecchia P. Prognostic value of ambulatory blood pressure: current evidence and clinical implications. Hypertension Mar 2000;35(3):844–51. [2] Pierdomenico SD, Lapenna D, Bucci A, et al. Cardiovascular outcome in treated hypertensive patients with responder, masked, false resistant, and true resistant hypertension. Am J Hypertens Nov 2005;18(11):1422–8. [3] Clement DL, De Buyzere ML, De Bacquer DA, et al. Prognostic value of ambulatory blood-pressure recordings in patients with treated hypertension. N Engl J Med Jun 12 2003;348(24):2407–15. [4] Wolf-Maier K, Cooper RS, Kramer H, et al. Hypertension Treatment and Control in Five European Countries, Canada, and the United States. Hypertension Jan 1 2004;43(1):10–7. [5] Staessen JA, Byttebier G, Buntinx F, Celis H, O'Brien ET, Fagard R. Antihypertensive treatment based on conventional or ambulatory blood pressure measurement. A randomized controlled trial. Ambulatory Blood Pressure Monitoring and Treatment of Hypertension Investigators. JAMA Oct 1 1997;278(13):1065–72. [6] Lorgelly P, Siatis I, Brooks A, Slinn B, Millar-Craig MW, Donnelly R, et al. Is ambulatory blood pressure monitoring cost-effective in the routine surveillance of treated hypertensive patients in primary care? Br J Gen Pract Oct 2003;53(495):794–6. [7] Myers MG, Reeves RA, Oh PI, Joyner CD. Overtreatment of hypertension in the community? Am J Hypertens May 1996;9(5):419–25.