MUNICH — Acute severe hypertension is a common, suboptimally treated condition with a high recurrence rate and surprisingly high morbidity and mortality.
These are the principal lessons of the just-completed large national Studying the Treatment of Acute Hypertension (STAT) registry, Dr. Christopher B. Granger said at the annual congress of the European Society of Cardiology.
The STAT observational registry documented 90-day mortality and readmission rates following an episode of acute severe hypertension (ASH), rates comparable with those typically encountered in patients with acute heart failure or an acute coronary syndrome.
These and other sobering STAT findings “reinforce the major need to improve prevention and treatment of this understudied condition,” stressed Dr. Granger, a cardiologist at Duke University, Durham, N.C., and chairman of the STAT steering committee.
ASH involving blood pressures in excess of 180/110 mm Hg, or greater than 140/90 mm Hg with subarachnoid hemorrhage, occurs in 1%–2% of the 72 million Americans with chronic hypertension. At some busy urban emergency departments, ASH accounts for up to 25% of all patients seen. Yet little contemporary information is available about the characteristics of affected patients, their treatment, or outcomes. This was the impetus for STAT.
Dr. Granger reported on 1,588 adults who received intravenous antihypertensive agents for ASH within 24 hours of presenting at 25 nationally representative participating U.S. hospitals.
The mean age of STAT registry participants was 58 years. About one-half were women, and 56% were African American. Overall, 89% of participants had a history of chronic hypertension, 35% were diabetic, 31% had chronic kidney disease, 15% had a history of drug abuse, and 27% had previously been hospitalized for ASH. Nonadherence to medications for chronic hypertension was deemed a contributing factor in 25% of ASH episodes.
Roughly one-quarter of patients were admitted for acute hypertension, another quarter for stroke or other neurologic complications, and one-quarter for heart failure or other cardiovascular conditions.
The median hospital length of stay was 5 days. Roughly half of patients were admitted to the intensive care unit. During their stay, 48% of patients had brain imaging by CT or MRI and 45% had an echocardiographic examination—yet disturbingly, a mere 13% had a documented funduscopic exam, Dr. Granger noted.
Among the key STAT findings were:
▸ Poor outcomes. In-hospital mortality was 6.9% and 90-day mortality was 11%. The 90-day readmission rate was 37%, and 9.3% of patients were rehospitalized within 90 days for recurrent ASH.
▸ Lengthy time to blood pressure control. The median time to drive systolic blood pressure below 160 mm Hg was 4 hours. Moreover, following initial control, fully 60% of patients experienced a rebound to greater than 180 mm Hg. Also, 4% of patients had iatrogenic hypotension, in most cases requiring vasopressors.
▸ Variable treatment approaches. Intravenous antihypertensive therapy was administered within 1 hour in 47% of patients and within 3 hours in 74%. Two-thirds of patients required two or three intravenous antihypertensive drugs. The first intravenous drug employed was labetalol in 32% of cases and metoprolol in 17%, followed in descending order by nitroglycerin, hydralazine, nicardipine, and sodium nitroprusside. Nicardipine was the only drug that served as monotherapy in the majority of treated patients.
▸ Inadequate follow-up. ASH is a life-threatening condition, yet 65% of patients had no documentation in the medical record of a follow-up appointment being scheduled or attended.
Ongoing STAT analyses include efforts to identify risk factors for recurrence, as well as the most effective ways to lower high blood pressures without exacerbating damage to the kidneys and other organs.
“We're trying to analyze the relationship between patterns of control and outcome. There are interesting data from the ECLIPSE [Evaluation of Clevidipine in the Postoperative Treatment of Hypertension Assessing Safety Events] trial showing that patients with perioperative hypertension who get into and stay within a target blood pressure range have better outcomes; it was an independent predictor. Whether that's the case in this population with acute severe hypertension is a very important question we currently lack information on,” he continued.
Both the STAT registry and ECLIPSE were funded by the Medicines Company. Dr. Granger has received research grants from and served as a paid consultant to the company.
In the STAT registry of 1,588 patients, in-hospital mortality was 6.9% and 90-day mortality was 11%. DR. GRANGER