Another paper raises new questions about applying SPRINT in the real world
Applying the intense blood pressure goals used in SPRINT in a real world elderly population might lead to a dramatic increase in injurious falls, according to a new study from Ireland published in JAMA Internal Medicine.
The Systolic Blood Pressure Intervention Trial (SPRINT) showed that high risk adults with hypertension had a significant reduction in cardiovascular events and death when treated to an aggressive systolic blood pressure (BP) target of 120 mm Hg instead of 140 mm Hg. But the results of the trial have been the subject of considerable controversy. One area of concern has been the application of the results in elderly people due to fears that they may be more likely to fall if their blood pressure drops too low.
Donal Sexton (Trinity College, Dublin) and colleagues compared the falling rate in people 75 years of age or older participating in The Irish Longitudinal Study on Ageing (TILDA) with a comparable group in the control arm of SPRINT. The rates of injurious falls and syncope were much greater in the TILDA population. Injurious falls were reported in 27.3% of the people in the TILDA group compared with only 5.5% in the SPRINT group. Syncope was reported in 13.3% versus 2.4%.
“Given the high baseline rates of falls and syncope, any increase in these rates due to intensive treatment of hypertension could result in harm,” the authors concluded.
Sripal Bangalore (NYU) said that the study “proves the dictum that real world patients may not be the same as those in clinical trials!”
But Sanjay Kaul (Cedars-Sinai) warned that the differences in outcome suggests the TILDA cohort is materially different from the SPRINT cohort. He pointed out that it is unclear whether the TILDA exclusion criteria were similar to the criteria used in SPRINT. “Furthermore,” he noted, “no information about medications – the type, number, and dose of meds, especially BP lowering meds, is provided.” These shortcoming limit the ability to generalize from this paper, said Kaul.
George Bakris (University of Chicago) agreed that the study “has statistical limitations” but that “the point the authors make about injurious falls and syncope is important especially among those over 75 years of age.” Bakris said that many older patients should be treated to blood pressure levels much lower than 160 mm Hg, and perhaps below 140 mm Hg, “if they can tolerate it.” But, he argued, “clinical judgement in some cases needs to trump outcome data as not everyone especially those with poor vascular compliance, i.e., pulse pressure >80, can tolerate very low blood pressures without having symptoms of tiredness and lightheadedness. This is exemplified in a recent study by Torjesen and colleagues with data from Framingham. They noted that higher aortic stiffness was associated with a blunted orthostatic increase in MAP, even in middle age.” Bakris said that this group was not well represented in SPRINT.
Sverre Kjeldsen (Oslo University Hospital) has been vocal in criticizing the technique used to measure blood pressurein SPRINT. But, he said, this analysis shows “that the low BP targets suggested by SPRINT will just cause harm around in the world — whether BP is measured by one method or another.” The problem is especially acute in the elderly and very old, he said. “In people above the age of 80 we treat BP above 160 mm Hg and the target should be between 140 and 150 mm Hg — according to the only quality study that has been done (HYVET). And there is emphasis on standing (upright) BP in the old which cannot be too low.”
This article has been republished from Larry’s blog CardioBrief as part of a licensing agreement between Everyday Health and the limbic.