What are the Bruce protocol stress test protocols for patients with hypertension and cardiovascular stress?

From the Guidelines

The Bruce protocol is a well-established cardiac stress test where patients walk on a treadmill with gradually increasing speed and incline every three minutes while monitoring heart rate, blood pressure, and ECG changes, and is the preferred method for patients with hypertension and cardiovascular stress who are able to perform routine activities of daily living without difficulty. For patients with hypertension and cardiovascular stress, the goal of exercise testing is to achieve high levels of exercise, which can provide a higher physiological stress than pharmacological testing, and to document the extent and severity of ECG changes and angina at a given workload 1. The standard Bruce protocol initiates exercise at 3.2 to 4.7 metabolic equivalents (METs) of work and increases by several METs every 2 to 3 minutes of exercise, and most activities of daily living require approximately 4 to 5 METs of physical work to perform 1. Some key points to consider when using the Bruce protocol for patients with hypertension and cardiovascular stress include:

• The test typically requires 12-lead ECG monitoring, blood pressure measurements at each stage, and observation for symptoms like chest pain or shortness of breath.
• Patients should wear comfortable clothing and athletic shoes, avoid heavy meals before testing, and may need to temporarily discontinue certain cardiac medications like beta-blockers that could affect heart rate response.
• Modified versions of the Bruce protocol exist for elderly or deconditioned patients, starting at lower intensities.
• The test helps diagnose coronary artery disease, determine functional capacity, and guide treatment decisions by revealing how the heart performs under physical stress. It is also important to note that optimal candidates for exercise testing must possess sufficient functional capacity to attain maximal, volitional stress levels, and patients incapable of at least moderate physical functioning or with disabling comorbidity should be referred for pharmacological stress imaging 1. In the setting of submaximal exercise and a negative stress ECG, consideration should be given to performing additional testing with pharmacological stress imaging to evaluate for inducible ischemia 1.

From the Research

Bruce Protocol Stress Test Protocols

The Bruce protocol is a commonly used stress test protocol for evaluating cardiovascular health. For patients with hypertension and cardiovascular stress, the following points are relevant:

• The Bruce protocol is considered "steep" and may not be suitable for all patients, particularly those with hypertension, diabetes, smoking, and high body mass index 2.
• A prediction model has been developed to identify patients who may not be suitable for the Bruce protocol, taking into account factors such as hypertension, diabetes, smoking, body mass index, and age 2.
• The modified Bruce protocol has been compared to the standard Bruce protocol, with results showing that the modified protocol has a lighter initial increment but may decrease the capacity for peak exercise due to peripheral fatigue 3.
• The Bruce protocol has been shown to be superior to other exercise protocols, such as the modified Naughton test, for detecting ischemic abnormalities in post-myocardial infarction patients 4.
• The prognostic value of functional capacity in different exercise protocols, including the Bruce protocol, has been evaluated, with results showing that higher estimated metabolic equivalents (METs) are associated with lower mortality, but the prognostic value is not transferable across different tests 5.
• The diagnostic accuracy of exercise treadmill testing and stress echocardiography for detecting obstructive coronary artery disease in patients aged ≥ 70 years has been compared, with results showing that stress echocardiography is more accurate than exercise treadmill testing for ruling in or ruling out obstructive coronary artery disease in this population 6.

Key Considerations

• Patients with hypertension and cardiovascular stress should be carefully evaluated before undergoing a Bruce protocol stress test.
• The modified Bruce protocol may be a suitable alternative for patients who are not able to tolerate the standard Bruce protocol.
• The choice of exercise protocol should be individualized based on the patient's specific needs and health status.
• The prognostic value of functional capacity should be considered in the context of the specific exercise protocol used.
• Stress echocardiography may be a useful diagnostic tool for detecting obstructive coronary artery disease in patients aged ≥ 70 years.