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A target systolic blood pressure (SBP) below 120 mm Hg leads to better outcomes in ambulatory elderly patients than a target below 140 mm Hg, according to a subanalysis of SPRINT (Systolic Blood Pressure Intervention Trial).

SPRINT included a prespecified subgroup of adults ages 75 and older who had hypertension but did not have diabetes. The current study compared the effects of intensive and standard SBP targets in these 2,636 patients. "Intensive" was defined as below 120 mm Hg, while "standard" was defined as below 140 mm Hg.

The primary composite outcome for cardiovascular disease was nonfatal myocardial infarction, acute coronary syndrome that did not result in a myocardial infarction, nonfatal stroke, nonfatal acute decompensated heart failure, and death from cardiovascular causes. The secondary outcome was all-cause mortality. The results of the subgroup analysis were presented last week at the American Geriatrics Society Annual Scientific Meeting and were published online May 19 by JAMA.

The mean age of the participants was 79.9 years, and 37.9% were women. A total of 1,317 were randomly assigned to the intensive treatment group, and 1,319 were randomly assigned to the standard treatment group. Follow-up data were complete for 95.2% of patients. At a median follow-up of 3.14 years, the rate of the primary composite outcome was significantly lower in the intensive treatment group than in the standard treatment group (hazard ratio [HR], 0.66; 95% CI, 0.51 to 0.85), as was all-cause mortality (HR, 0.67; 95% CI, 0.49 to 0.91).

The overall rate of serious adverse events did not differ between the treatment groups (48.4% in the intensive therapy group vs. 48.3% in the standard therapy group; HR, 0.99; 95% CI, 0.89 to 1.11). However, the intensive therapy group had higher absolute rates of hypotension (2.4% vs. 1.4%; HR, 1.71; 95% CI, 0.97 to 3.09), syncope (3.0% vs. 2.4%; HR, 1.23; 95% CI, 0.76 to 2.00), electrolyte abnormalities (4.0% vs. 2.7%; HR, 1.51; 95% CI, 0.99 to 2.33), and acute kidney injury (5.5% vs. 4.0%; HR, 1.41; 95% CI, 0,98 to 2.04) but a lower rate of injurious falls (4.9% vs. 5.5%; HR, 0.91; 95% CI, 0.65 to 1.29).

The authors noted that SPRINT was designed to enhance recruitment of older adults but did not stratify randomization by age. In addition, they said, the generalizability of their results is limited because some elderly patients, such as nursing home residents and patients with type 2 diabetes or previous stroke, were excluded from SPRINT.

However, despite these and other limitations, the researchers concluded that treating to lower SBP targets in ambulatory adults ages 75 years and older led to better outcomes, specifically lower rates of all-cause mortality and cardiovascular events. They called for further analyses of SPRINT data to help quantify the burdens, costs, and benefits of intensive treatment but said their results "have substantial implications for the future of intensive [blood pressure] therapy in older adults because of this condition's high prevalence, the high absolute risk for cardiovascular disease complications from elevated [blood pressure], and the devastating consequences of such events on the independent function of older adults."

An accompanying editorial also detailed the limitations of both the current study and SPRINT but said the results should trigger reconsideration of optimal blood pressure goals for patients ages 75 and older. The editorialist said that current evidence supports a stepwise approach to treatment, starting with an SBP goal of less than 140 mm Hg and titrating, with careful monitoring, to a goal of 130 mm Hg if the first goal is well tolerated.

"Achieving the SBP goal of less than 130 mm Hg may be challenging for clinicians, because doing so could require use of additional medications, more careful monitoring, and more frequent clinic visits," the editorialist wrote. "Nevertheless, the important results [of the current study] cannot be discounted, and unless unexpected adverse effects are observed on further examination of the trial data, then major changes in treatment goals for patients 75 years or older with hypertension will be warranted."

Kevin A. Brown, PhD; Makoto Jones, MD; Nick Daneman, MD; Frederick R. Adler, PhD; Vanessa Stevens, PhD; Kevin E. Nechodom, BSc; Matthew B. Goetz, MD; Matthew H. Samore, MD; and Jeanmarie Mayer, MD

Background: Although clinical factors affecting a person's susceptibility to Clostridium difficile infection are well-understood, little is known about what drives differences in incidence across long-term care settings.

Objective: To obtain a comprehensive picture of individual and regional factors that affect C difficile incidence.

Design: Multilevel longitudinal nested case–control study.

Setting: Veterans Health Administration health care regions, from 2006 through 2012.

Participants: Long-term care residents.

Measurements: Individual-level risk factors included age, number of comorbid conditions, and antibiotic exposure. Regional risk factors included importation of cases of acute care C difficile infection per 10 000 resident-days and antibiotic use per 1000 resident-days. The outcome was defined as a positive result on a long-term care C difficile test without a positive result in the prior 8 weeks.

Results: 6012 cases (incidence, 3.7 cases per 10 000 resident-days) were identified in 86 regions. Long-term care C difficile incidence (minimum, 0.6 case per 10 000 resident-days; maximum, 31.0 cases per 10 000 resident-days), antibiotic use (minimum, 61.0 days with therapy per 1000 resident-days; maximum, 370.2 days with therapy per 1000 resident-days), and importation (minimum, 2.9 cases per 10 000 resident-days; maximum, 341.3 cases per 10 000 resident-days) varied substantially across regions. Together, antibiotic use and importation accounted for 75% of the regional variation in C difficile incidence (R2 = 0.75). Multilevel analyses showed that regional factors affected risk together with individual-level exposures (relative risk of regional antibiotic use, 1.36 per doubling [95% CI, 1.15 to 1.60]; relative risk of importation, 1.23 per doubling [CI, 1.14 to 1.33]).

Limitations: Case identification was based on laboratory criteria. Admission of residents with recent C difficile infection from non–Veterans Health Administration acute care sources was not considered.

Conclusion: Only 25% of the variation in regional C difficile incidence in long-term care remained unexplained after importation from acute care facilities and antibiotic use were accounted for, which suggests that improved infection control and antimicrobial stewardship may help reduce the incidence of C difficile in long-term care settings.

Primary Funding Source: U.S. Department of Veterans Affairs and Centers for Disease Control and Prevention.

Steven P. Dehmer, PhD; Michael V. Maciosek, PhD; Thomas J. Flottemesch, PhD; Amy B. LaFrance, MPH; and Evelyn P. Whitlock, MD, MPH

Background: Evidence indicates that aspirin is effective for the primary prevention of cardiovascular disease (CVD) and colorectal cancer (CRC) but also increases the risk for gastrointestinal (GI) and cerebral hemorrhages.

Objective: To assess the net balance of benefits and harms from routine aspirin use across clinically relevant age, sex, and CVD risk groups.

Design: Decision analysis using a microsimulation model.

Data Sources: 3 systematic evidence reviews.

Target Population: Men and women aged 40 to 79 years with a 10-year CVD risk of 20% or less, and no history of CVD and without elevated risk for GI or cerebral hemorrhages that would contraindicate aspirin use.

Time Horizon: Lifetime, 20 years, and 10 years.

Perspective: Clinical.

Intervention: Low-dose aspirin (≤100 mg/d).

Outcome Measures: Primary outcomes are length and quality of life measured in net life-years and quality-adjusted life-years. Benefits include reduced nonfatal myocardial infarction, nonfatal ischemic stroke, fatal CVD, CRC incidence, and CRC mortality. Harms include increased fatal and nonfatal GI bleeding and hemorrhagic stroke.

Results of Base-Case Analysis: Lifetime net quality-adjusted life-years are positive for most adults initiating aspirin at ages 40 to 69 years, and life expectancy gains are expected for most men and women initiating aspirin at ages 40 to 59 years and 60 to 69 years with higher CVD risk. Harms may exceed benefits for persons starting aspirin in their 70s and for many during the first 10 to 20 years of use.

Results of Sensitivity Analysis: Results are most sensitive to the relative risk for hemorrhagic stroke and CVD mortality but are affected by all relative risk estimates, baseline GI bleeding incidence and case-fatality rates, and disutilities associated with aspirin use.

Limitations: Aspirin effects by age are uncertain. Stroke benefits are conservatively estimated. Gastrointestinal bleeding incidence and case-fatality rates account only for age and sex.

Conclusion: Lifetime aspirin use for primary prevention initiated at younger ages (40 to 69 years) and in persons with higher CVD risk shows the greatest potential for positive net benefit.

Primary Funding Source: Agency for Healthcare Research and Quality.

More than 1 in 3 patients with atrial fibrillation and intermediate to high risk of stroke are prescribed aspirin instead of oral anticoagulants, contrary to guidelines, a recent study found.

Researchers examined data from the American College of Cardiology's PINNACLE Registry on 210,380 patients with a CHADS2 score greater than or equal to 2 between January 2008 and December 2012 and, in a secondary analysis, data on 294,642 patients with a comparable CHA2DS2-VASc score during the same timeframe. The goal was to examine the prevalence and predictors of treatment with aspirin only versus oral anticoagulation in patients with atrial fibrillation who were at risk for stroke and who were being treated by cardiovascular subspecialists. Results were published by the Journal of the American College of Cardiology on June 20.

A total of 210,830 patients were included in the CHADS2 group, and 294,642 patients were in the CHA2DS2-VASc group. Among the CHADS2 group, 38.2% were treated with aspirin alone and 61.8% were treated with oral anticoagulants. Among the CHA2DS2-VASc group, 40.2% were treated with aspirin and 59.8% were treated with oral anticoagulants. For both groups, patients who were prescribed aspirin were younger, had a lower body mass index, were more likely to be female, and were more likely to have another medical condition, including diabetes, hypertension, high cholesterol, coronary artery disease, prior heart attack, prior coronary artery bypass graft surgery, or peripheral artery disease.

After multivariable adjustment, hypertension, dyslipidemia, coronary artery disease, prior myocardial infarction, unstable and stable angina, recent coronary artery bypass grafting, and peripheral arterial disease were associated with prescription of aspirin alone. Meanwhile, male sex, higher body mass index, previous stroke or transient ischemic attack, previous systemic embolism, and congestive heart failure were associated with more frequent prescription of oral anticoagulation.

The authors noted that cardiologists may be prescribing aspirin instead of oral anticoagulants because they think that aspirin is as efficacious as oral anticoagulants. "Because many of the predictors of aspirin use alone include conditions that may warrant aspirin therapy regardless of the presence of [atrial fibrillation], much of the underutilization of appropriate anticoagulant agents may be driven by either the perception that aspirin by itself is sufficient or that the risk of aspirin plus anticoagulation is not worth the benefit," the authors wrote.

An editorial noted that clinicians may not realize that aspirin puts patients at risk for bleeding while providing no protection from stroke and that new and definitive evidence demonstrates that anticoagulation, not aspirin, is the treatment of choice to prevent strokes related to atrial fibrillation. The authors acknowledged that "The process of anticoagulation is not a particularly attractive proposition, entailing compliance with a long-term regimen that many patients and their physicians find burdensome, with inevitable nuisance, expense, annoying minor side effects, and infrequent, but devastating, complications, such as intracerebral hemorrhage, and with only an abstract future benefit for perhaps 4 or 5 of 100 patients who would suffer a stroke if they did not receive anticoagulation."

Still, the editorial stated, "Physicians and their patients should not sidestep the real risks of thromboembolism due to atrial fibrillation and the benefits of real anticoagulation, relying instead on aspirin, which has bleeding risk, but little, if any, therapeutic benefit. 'Take 2 aspirin and call me in the morning' is not appropriate treatment for a patient with atrial fibrillation at risk for thromboembolism."