Blood Pressure Control Pivotal in Reducing Stroke Risk in Patients With Atrial Fibrillation

About three out of four people who have a stroke for the first time have high blood pressure and atrial fibrillation is present in about one out of five strokes.

Although atrial fibrillation (AF) can feel weird and frightening, an “attack of AF” usually doesn’t have harmful consequences by itself. The real danger is the increased risk for stroke. For the first time, new research presented at ESC Congress shows that blood pressure control is pivotal in reducing major bleeding and stroke risk in patients with AF.

Even when symptoms are not noticeable, AF can increase a person’s risks for stroke and related heart problems. The range of variability in a patient's systolic blood pressure (SBP) from visit to visit was strongly associated with their risk of adverse outcomes, reported Dr Marco Proietti, MD, from the Institute of Cardiovascular Sciences, University of Birmingham.

Catheter Ablation: A Better Treatment For Atrial Fibrillation
Catheter ablation procedure in treating patients with atrial fibrillation (AF) was found to be better than the conventional drug therapies.

‘Many medications used to treat atrial fibrillation (AF) also reduce blood pressure (BP). The relation between BP and mortality is unclear in patients with AF.’

"Our findings suggest that consistency in blood pressure control, beyond the single measurement, is very important, and this appears to be the case across all types of AF patients, irrespective of age, blood pressure history, blood pressure level or clotting risk," said Dr. Proietti.

"Interventions aimed at reducing blood pressure variability over the long term, such as optimizing the medications and improving adherence are strongly needed," he added.

The study was a post-hoc analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, a prospective randomized comparison of two treatment strategies in patients with AF.

Incidence of Undiagnosed Atrial Fibrillation in High-risk Patients
Atrial fibrillation affects millions of people worldwide. In high-risk patients, the detection rate of atrial fibrillation lasting six or more minutes at 18 months was 29%.

In total, 3,843 patients from AFFIRM were included in the current analysis, for whom visit-to-visit variability (VVV) in mean SBP had been recorded at 2, 4, 8 and 12 months and then every 4 months after enrolment.

The patients were categorised into four quartiles based on their mean standard deviation in SBP: those who SBP varied by less than 10.09 mmHg from visit to visit (1st quartile); and then those with variations of10.09-13.85 mmHg (2nd), 13.86-17.33 mmHg (3rd) and ?17.34 mmHg (4th).

Exploring Mathematical Methods to Measure the Effectiveness of Treating Atrial Fibrillation
A complex mathematical method to measure electrical communications within the heart that can successfully predict the effectiveness of catheter ablation.

After a mean follow-up of 3.6 years, 149 strokes and 248 major bleeding events had been recorded, with a clear pattern of increasing risk with each elevation in quartile.

Specifically stroke rate progressively increased from 2.5% to 3.0% to 3.8% and 6.2% from the first to the fourth quartile (p<0.001) and similarly, the major bleeding rate was directly related to SBP-VVV quartiles (10.8%, 11.2%, 15.6%, 20.8% respectively; p<0.001).

High Rates of Stroke History in Asymptomatic Atrial Fibrillation Patients
Screening is needed to identify atrial fibrillation patients with no symptoms so that stroke prevention treatment can be given.

After adjusting for variables, the analysis showed that patients in the third and fourth quartiles were at significantly increased risk of stroke (hazard ratio [HR]: 1.85 and 2.33, p=0.042 and p=0.004 respectively) and major bleeding (HR: 1.92 and 2.88, p=0.009 and p<0.001 respectively).

Dr. Proietti said these outcomes will likely translate to higher mortality in patients in the higher quartiles.

"A better effort in controlling blood pressure in the clinical follow-up is pivotal to obtain a better management of patients with atrial fibrillation and improvement of outcomes", he reiterated.

Source-Eurekalert