The machines, which are valued at approximately €8,000 in total, record an average of 70 to 80 blood pressure measurements in 24hrs when worn by an individual, and have been introduced to not only improve diagnosis of hypertension but also help identify risks for adverse events that clients with hypertension may be faced with.
Lighthouse clinics, like most antiretroviral therapy (ART) clinics in Malawi, use the standard procedure of measuring the blood pressure of clients on clinic appointment dates at vital signs stations, but as said by Prof Steffen during the ceremony, one measurement alone cannot accurately tell if a client is indeed hypertensive. He explained that ambulatory blood pressure monitoring (ABPM) using a series of measurements done as the client performs day to day activities, would better determine if clients have true hypertension. This would reduce the number of white coat hypertension cases; cases in which a client exhibits a blood pressure level above the normal range at the clinic due to anxiety or tense of being in the clinical setting but not truly hypertensive.
Additionally, the donated machines have an in-built feature called Pulse Wave Analysis which estimates central blood pressure; the blood pressure which affects the brain as well as the coronary arteries which give oxygen to the heart muscles. There is a strong correlation between central blood pressure and vascular damage and pulse wave analysis helps to predict the stiffness of the blood vessels in comparison to one’s age.
The machine’s Pulse Wave Analysis technique presents the findings in an easy to understand message. It uses smiley faces; the sad face, the happy face, and the indifferent face, in different colors; green, yellow and red, to inform whether a client’s blood vessels are of the same biological age or older. For example, if a client’s results show a red sad face, this means his/her blood vessels appear older than the client’s age.
With these techniques, Professor Steffen said he hopes the clinical team at the Lighthouse will be able to build an individualized risk management program for the clients. Stating that clients with already existing vessel damage, need close control of all cardiovascular risk factors such as hypertension, diabetes, high cholesterol, obesity, and smoking. He added that “by having this technique on board, it is easier to estimate the individual patient risk.”
Representing the Lighthouse Clinical Management Team, Dr Beatrice Mwagomba, Lighthouse Medical Director, said “It is a dream come true to have a machine that already estimates and predicts the cardiovascular risk of an individual. We know that in Malawi, 32.9% of adults are found with high blood pressure (although Lighthouse had only registered 8% hypertension within the LighTen Study cohort). And it is also known that HIV infection and some ARVs increase the cardiovascular risk of a person. Therefore, having the means to predict whether a client is likely to have an adverse cardiovascular event such as, heart attack or stroke enables the clinical staff to manage the patient accordingly.” She concluded by saying she was thankful for the donation and hoped that at the end of the Study, when the benefits of the machines in a Malawian setting are known, the findings of the 24 hour BP monitoring in the LighTen Study would later be applied to the general Lighthouse cohort and probably make recommendations for a wider (national) application of the intervention.
Expressing his sincere gratitude on behalf of the Lighthouse Trust, the Executive Director, Prof Sam Phiri, said, “We appreciate Professor Michael Steffen for this initiative and we would like to thank the rest of the collaborative team within the Universities of Heidelberg and Cologne and also the company which has provided the machines. We will use them and we know they will make an impact on our service! “
The aim of the LighTen Study is to describe baseline clinical characteristics and long-term outcomes of clients using Tenofovir based antiretroviral therapy (5A) at the Lighthouse Clinics. Some of the specific objectives include to determine the prevalence of renal dysfunction at enrolment and during follow-up among adult HIV-infected individuals starting ART, to determine the prevalence of Hepatitis B and C infections among adult HIV-infected individuals starting ART and during treatment follow-up, and to determine the prevalence of non-communicable co-morbidities during treatment follow-up of HIV-infected individuals starting ART and during treatment follow-up. The blood pressure monitoring sub-study will contribute to the last objective of the LighTen Study.