These contemporary data derived from the Euro-STAT study demonstrate heterogeneous patterns of care for patients presenting with acute elevation of BP across a range of acute care settings, with high rates of morbidity and mortality. Of the 791 patients included in Euro-STAT, 48% were treated for acute hypertension in the ICU. Many of them had undergone surgery and developed severe hypertension postoperatively, 29% developed it perioperatively and 23% developed it in the ED. Median BP was higher among patients treated in the ED (200/100 mmHg) than in those treated in the ICU (160/73 mmHg) or perioperatively (160/80 mmHg).
The Studying the Treatment of Acute Hypertension (STAT) registry in the United States [9
] involved patients with a qualifying episode of acute, severe hypertension (that is, (1) SBP greater than 180 and/or DBP greater than 110 mmHg or (2) SBP above 140 mmHg and/or DBP greater than 90 mmHg when presenting with subarachnoid haemorrhage) who received IV antihypertensive therapy in a critical care setting. Compared with the STAT study, the patients' median age in the Euro-STAT study was higher (69 vs 58 years) and fewer patients had a history of hypertension (62% vs 89%). Overall, the median BP was lower in the Euro-STAT study than in the STAT study (166/80 vs 200/110 mmHg). This finding could indicate that patients in the Euro-STAT study had less severe hypertension, or it could be related to the different qualifying criteria and hence the distribution of patients in the STAT studies. In Euro-STAT, perioperative patients were also included, and there were many more ICU patients (mainly in a postoperative context) than there were in the STAT study.
The decision to amalgamate ED, perioperative and ICU patients was made because the purpose of this descriptive study was to evaluate the efficacy of IV therapy for the control of elevated BP level in different locations within a hospital, thereby assessing similarities and differences in treatments and outcomes in different contexts.
The first antihypertensive drug used varied by treatment location. In the ICU, nitroglycerine was by far the most widely used (60%); in the ED, furosemide was used in 34% of patients and nitroglycerine was used in 27%; and perioperatively, urapidil was used in 34% of patients and clonidine was used in 28%. The high use of furosemide in the ED (34%) indicates that pulmonary oedema associated with high BP was the likely primary diagnosis, which is backed up by the higher rates of new or worsened acute coronary syndrome (17% vs 1.1% and 0.5%) and acute left ventricular dysfunction (19.4% vs 2.9% and 0.9%) in ED vs ICU and perioperative patients, respectively. In Euro-STAT overall, the most frequently used antihypertensive drugs were nitroglycerine (40%), urapidil (21%), clonidine (16%) and furosemide (8.3%). This pattern is very different from the results of the STAT study, where the most common initial antihypertensive drugs were labetalol (32%), metoprolol (17%), nitroglycerine (15%) and hydralazine (15%) [9
]. The variations in drug use between the Euro-STAT and STAT studies may reflect differences in the drugs available in these regions. The percentage of patients who required a second IV antihypertensive was 34% in both the Euro-STAT and STAT studies.
This variability in treatment between continents, studies and hospital departments is not surprising, given the paucity of evidence regarding the superiority of one drug over another and the absence of guidelines for the treatment of acute hypertension. There are, however, various papers that have provided recommendations that are not evidence-based. Acute hypertension can be split into hypertensive emergencies (severe BP elevation with evidence of impending or progressive end-organ damage) and hypertensive urgencies (severe BP elevation without progressive target organ dysfunction) [1
]. In general, hypertensive urgencies can be treated with oral antihypertensive drugs [11
], and researchers who published a recent meta-analysis found angiotensin-converting enzyme inhibitors to be superior to calcium channel blockers [12
]. Hypertensive emergencies generally require IV treatment to achieve a rapid decrease in BP, and patients admitted to these care settings may be sicker than patients treated with oral agents. Recommendations (based on expert consensus due to a lack of clinical trials) for which antihypertensive to use based on different disease states are shown in Table [13
Recommended treatments for hypertensive emergenciesa
While nitroglycerine should be used as an adjunctive therapy, the high rates of use in the Euro-STAT population likely reflect familiarity with its use, together with its ease of administration, titration and rapid reversibility. In the ED, the ICU and perioperatively, 4.4%, 8.4% and 10% of patients, respectively, had hypotension within 72 hours of the start of treatment, resulting in (1) discontinuation of the antihypertensive drug or (2) treatment with vasopressors, fluids or reverse Trendelenburg positioning. The overall incidence of hypotension in the Euro-STAT study was higher than that in the STAT study (8.1% vs 4.0%) [9
As expected, mortality rates at discharge from the ICU, ED or surgical department in the Euro-STAT study were highest among ICU patients (3.4% vs 1.1% of ED patients and 0% of perioperative patients). Total in-hospital mortality in the Euro-STAT study was highest among ED patients (5.7% vs 5.1% of ICU patients and 2.3% of perioperative patients), which is lower than the comparable rate in the STAT study (6.9%) [9
]. New or worsened end-organ damage was observed in 43% of ED patients, 15% of ICU patients and 6.6% of perioperative patients.
The observational Euro-STAT registry is a relatively small data set, and the sites may not be representative of all hospitals in Europe. Treatment choices may therefore be biased by institution choices. Also, populations of acute hypertension are heterogeneous and are likely to differ by country. Amalgamation of all countries into one data set therefore gives an overview, but no country-specific data. As our entry criteria required the physician to initiate IV antihypertensive therapy, there was no comparison with other patients in relation to morbidity. Also, we do not have complete information on post-hospital discharge follow-up. Furthermore, we do not know what happened to patients for whom a reduction in BP was not achieved despite treatment.