Absolute benefit greater in older patients in ASCOT-BPLA study
A post-hoc analysis of the ASCOT-BPLA study showed significant reductions in total cardiovascular events (CVE), cardiovascular mortality, and fatal and nonfatal stroke in patients ≥ 65 years old, and that compared to younger patients the absolute benefit was nearly 2-fold greater. The data was presented by Collier et al in a poster at the Scientific Sessions of the American Heart Association (4152/P17).
The finding of a greater benefit in ASCOT-BPLA is in contrast to the lesser benefit in the older cohort compared to the younger cohort in two previous analyses, the Prospective Studies Collaboration (Lancet 2002;360:1903-1913) and the Asia Pacific Cohort Studies Collaboration (J Hypertens 2003;21:707-716), the authors stated.
In the ASCOT-BPLA analysis, 8,137 patients ≥65 years old were compared to 11,120 patients <65 years to determine the safety and efficacy of amlodipine-based versus atenolol-based antihypertensive therapy. No safety differences were found between the two age cohorts.
The mean age in the older cohort was 71 years, 26% were women, and 96% were Caucasian, while in the younger cohort the mean age was 57 years, 21% were women, and 96% Caucasian. Concomitant atorvastatin use was similar in both age groups at 25.4% to 28%.
In the older cohort, patients had:
- Higher systolic and lower diastolic blood pressures (168/92 mmHg vs 161/97 mmHg).
- Greater use of prophylactic aspirin (26% vs 14%).
- Higher rates of stroke and transischemic attacks (15% vs 8%).
In the younger cohort, patients had:
- Higher fasting triglyceride (172 mg/dL vs 150 mg/dL).
- Higher heart rate (73 bpm vs 70 bpm).
- Higher BMI (29 kg/m2 vs 28 kg/m2).
- Greater consumption of alcohol (9 units vs 7 units/week).
- More current smokers (39% vs 23%).
As reported in the main results, dramatic reductions were seen in the overall trial with both drug treatments. However, in the older cohort blood pressure was lowered to a greater degree with amlodipine-based treatment (4.2/2.2 mmHg, compared to 1.7/1.7 mmHg atenolol-based treatment). More drugs were needed with the atenolol-based treatment to control blood pressure to goal levels during the study.
Between-group blood pressure differences were determined to be a small contributor to the differences in outcomes, according to an analysis of the main results published by Poulter et al (Lancet 2005;366:907-913).
Key findings in the ASCOT-BPLA post-hoc analysis of benefit in older versus younger patients.
|
Amlodipine-based treatment
(n) |
Atenolol-based treatment
(n) |
Relative risk reduction (RRR) (%) |
Absolute risk reduction
(per 1000 pt years) |
P value
RRR |
Total CVE/procedures |
|
|
|
|
|
Total |
1362 |
1602 |
16 |
|
<0.0001 |
≥65 years |
739 |
886 |
17 |
7.9 |
<0.0001 |
<65 years |
623 |
716 |
15 |
3.8 |
0.0029 |
|
|
|
|
|
|
CV Mortality |
|
|
|
|
|
Total |
263 |
342 |
24 |
|
0.0010 |
≥65 years |
169 |
221 |
23 |
2.3 |
0.0098 |
< 65 years |
94 |
121 |
24 |
0.9 |
0.0499 |
|
|
|
|
|
|
Fatal/Nonfatal stroke |
|
|
|
|
|
Total |
327 |
422 |
23 |
|
0.0008 |
≥65 years |
198 |
262 |
30 |
3.9 |
0.0001 |
<65 years |
129 |
140 |
9 |
0.2 |
0.4211 |
|
Note from Website Editor Peter Nilsson, M.D., Department of Clinical Sciences Medicine University Hospital, Sweden:
"The findings of benefit for older patients in the ASCOT-BPLA study is of great clinical relevance. However, we still need data in the very elderly hypertensive patients, as for example evaluated in the ongoing HYVET trial."
|
