Aggressive BP control may help prevent left ventricular conduction disease: SPRINT post hoc analysis

The study, published in JAMA Cardiology, found that people randomized to the intensive systolic BP target of <120 mm Hg had remarkably less incident LV conduction disease (including fascicular and left bundle-branch block) over a median of 3.5 years in the trial than the looser target of <140 mm Hg (HR 0.74).

LV conduction disease predicts death and heart failure, and the implantation of a permanent pacemaker is the only strategy to mitigate its effects. Currently, there are no proven preventive strategies for this common condition. Therefore, Emilie K. Frimodt-Møller, Herlev and Gentofte Hospital, Copenhagen, Denmark, and colleagues aimed to determine the association between targeting intensive BP control and the risk of developing left ventricular conduction disease.

For this purpose, the researchers conducted a post hoc analysis of the 2-arm multicenter SPRINT trial that involved participants from 102 sites in the US and Puerto Rico. The study included adults aged 50 years and above with hypertension, and at least one other cardiovascular (CV) risk factor was included. For the post-hoc analysis, participants with baseline left ventricular conduction disease, ventricular pre-excitation, or ventricular pacing were excluded.

Participants were randomly allocated to a standard treatment group in which they received a systolic blood pressure target of less than 140 mm Hg or to the intensive treatment group in which participants received less than 120 mm Hg.

The study's primary outcome was incident left ventricular conduction disease, assessed by serial electrocardiography. The incident right bundle-branch block was examined as a negative control.

The study revealed the following findings:

• Among 3918 participants randomized to standard treatment and 3956 to intensive therapy (mean age, 67.6 years; 36% female) monitored for a median of 3.5 years, 203 developed left ventricular conduction disease.
• Older age (hazard ratio per 10-year increase [HR], 1.42), cardiovascular disease (HR, 1.46), and male sex (HR, 2.31) were associated with a higher risk of left ventricular conduction disease.
• Assignment to intensive treatment was associated with a 26% lower risk of left ventricular conduction disease (HR, 0.74).
• These findings persisted when incident ventricular pacing was included in the outcome and when considering death from all causes as a competing risk.
• The authors found no association between randomization assignment and right bundle-branch block was observed (HR, 0.95).

"Targeting intensive BP control was tied to a lower risk of left ventricular conduction disease, which indicates that conduction disease may be a modifiable outcome susceptible to prevention strategies," the researchers concluded.

Reference:

Frimodt-Møller EK, Vittinghoff E, Kaur G, Biering-Sørensen T, Soliman EZ, Marcus GM. Association Between Intensive vs Standard Blood Pressure Control and Incident Left Ventricular Conduction Disease: A Post Hoc Analysis of the SPRINT Randomized Clinical Trial. JAMA Cardiol. Published online May 03, 2023. doi:10.1001/jamacardio.2023.0845