Central Vs Brachial BP, Exercise, and Coronary Artery Disease

Summary

High blood pressure (BP) is a major risk factor for coronary artery disease (CAD), with 30-70% of CAD patients having elevated BP. The conventional method of measuring BP in the arm (brachial BP) may miss some cases, as individuals can have normal brachial pressure but elevated central systolic pressure, which is a more critical predictor of cardiovascular events. Lowering BP is a key objective in cardiac rehabilitation programs.

Examining BP responses after a single bout of exercise could help predict how effectively exercise lowers BP over time. There is a well-established reduction in BP, known as post-exercise hypotension (PEH), which occurs after exercise. This drop is typically around 8 to 9 mmHg and is observed in individuals with and without hypertension. However, it may not occur in people with CAD. The reason for this difference is unclear but may relate to individual variability in exercise responses.

No research has closely examined individual responses to PEH in people with CAD, and it remains unclear whether exercise affects central and brachial BP differently, as some medications do. Additionally, exercise intensity may influence the magnitude of the BP reduction post-exercise. Higher-intensity exercise tends to cause a more significant BP drop, both in hypertensive and non-hypertensive individuals, typically within 20 to 60 minutes post-exercise.

Therefore, the present study aimed to determine the acute effects of combined exercise at different intensities on central and brachial blood pressure in individuals with and without coronary artery disease.

The key research questions were:

1. Is the BP response of central and brachial arteries to acute combined exercise similar? How does coronary artery disease influence these BP responses? Is there individual variability among people with CAD?
2. Does high-intensity exercise, compared to moderate-intensity exercise, produce more pronounced changes in BP in the post-acute exercise period?

All participants were asked to:

Complete two combined exercise sessions - one moderate- and one high-intensity bout. The order of the sessions was randomly assigned, similar to flipping a coin.

BP was measured before and after each acute exercise bout in the laboratory. The researchers compared central and brachial BP responses between exercise intensities (high vs. moderate) and populations (individuals with and without CAD).

Conditions

• Coronary Arterial Disease (CAD)

Interventions

OTHER

High-intensity combined exercise

The main part consisted of interval cycling exercise, comprising 5x2 min at the second ventilatory threshold interspersed with 4x2 min at the first ventilatory threshold, followed by 2-min unloading pedalling. Subsequently, participants completed resistance exercises (2 sets of 12 repetitions), targeting the same muscle groups of the moderate-intensity exercise, at an intensity of 80% of their 1 repetition maximum.

OTHER

Moderate-intensity combined exercise

The main part of the exercise session consisted of an 18-min cycling continuous aerobic exercise at the first ventilatory threshold, followed by 2-min of unloading cycling. Subsequently, participants engaged in resistance exercises - 2 sets of 12 repetitions at 60% of their one repetition maximum. These resistance exercises were part of a machine-assisted circuit training program, encompassing Chest Press, Leg Curl, Low Row, Leg Press, Lat Pull-down, and Leg Extension.

Sponsors & Collaborators

• Egas Moniz - Cooperativa de Ensino Superior, CRL

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

55 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-02-01

Primary Completion

2020-03-15

Completion

2020-03-15

Countries

• Portugal

Study Locations