The neglected role of blood pressure in acute heart failure syndrome

• Hypertension
• coronary artery disease
• arrhythmias
• neurology
• stroke

To the Editor I read with interest Harinstein et al's review of clinical assessment in acute heart failure syndromes (AHFS).1 Initial assessment of AHFS included evaluation of important prognostic factors that influence treatment such as the presence of atrial fibrillation, acute pulmonary oedema and renal function. This is in accordance with the six-axis model described by Professor Gheorghiade. An important factor in the six-axis model, which has been neglected, is the role of blood pressure in the presentation and evaluation of AHFS. Blood pressure plays a critical role in the prognosis of acute heart failure and should be a central consideration in management decisions. Previous work by Professor Gheorghiade2 describes the central role of blood pressure in acute heart failure. Blood pressure is an independent predictor of mortality and morbidity in heart failure. AHFS can present with low, normal and high blood pressure and each of these groups have different pathophysiology and respond differently to treatment. It is important to distinguish between them in the evaluation of AHFS. High blood pressure in AHFS tends to be due to reactive hypertension caused by high sympathetic tone whereas low blood pressure reflects poor cardiac output.2 3 Studies have shown that elevated systolic blood pressure (SBP) is common in patients hospitalised with AHFS. These patients have a lower post-discharge mortality, lower rates of rehospitalisation and shorter duration of stay than those with low SBP. However, they also have an increased risk of morbid events. It is hypothesised that blood pressure may distinguish those with early or mid-stage disease (high SBP) from those with advanced disease (low SBP).4 Congestive symptoms were more likely in patients with high blood pressure at admission; however, during discharge patients with low SBP had more congestive symptoms. Patients with high blood pressure may respond to heart failure treatment differently from patients with low SBP; however, high blood pressure in AHFS is under-represented in clinical trials of heart failure drugs. Use of ACE inhibitors and β blockers in these patients may have beneficial antihypertensive effects whereas they are less used in heart failure with hypotension. Hypotension may represent low cardiac output and maintaining adequate blood pressure is a treatment priority in the management of these types of AHFS. High SBP showed better response to treatment; however, the re-hospitalisation rates and risk of morbid events were similar to those for low SBP. Better treatment response in patients with high SBP may have given the physician a false sense of security that these patients were not as ill as hypotensive AHFS patients, which may have resulted in less aggressive management. There were lower rates of left ventricular function assessment and aldosterone use in patients with high SBP.

Acute heart failure is often inadequately managed in hospitals resulting in poor prognosis and re-hospitalisation. One of the factors influencing good management is careful evaluation of blood pressure. The role of this important factor is often poorly understood and underestimated. Yet it is a clinical feature that makes a substantial difference to treatment response.