Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Cardiovascular Risk First Clinical Approach with the Pulse by Mass Index
- Enrique J. Sánchez-Delgado (1 October 2008)
|
|
|||
|
Enrique J. Sánchez-Delgado, Director of Medical Education.Internist. Clinical Pharmacologist Hospital Metropolitano Vivian Pellas, Managua, Nicaragua
Send response to journal:
|
The investigation of Gregorio Montalvo et. al. facilitates the evaluation of hypertensive patients in the developing countries. Cardiovascular diseases are the main cause of death worldwide and increasingly in developing countries. Therefore, it is essential to evaluate the global cardiovascular diseases risk (CVDR) in every patient and promote individual prevention strategies. Since the nineties, The Framingham Risk Score (FRS, NCEP- ATP III) became the most commonly used, but must be adapted to specific populations and individuals. At the same time, obesity has turned to be a global pandemic that threatens the outstanding advances in cardiovascular prevention, being a main risk factor for the metabolic syndrome, type 2 diabetes, hypertension, heart diseases, stroke and some types of cancer. Behavioural patterns are more important than genetic predisposition in their contribution to premature deaths. At the other hand, the importance of the resting heart rate (RHR) as a risk factor becomes increasingly clear. Since many years it is well known that animals with a rapid RHR have a shorter lifespan and vice versa, and that drugs like beta-blockers reduce mortality, while rapid and potent vasodilators that reduce the blood pressure but increase pulse rate and retain water, do not reduce or rather increase the mortality. For example, the mouse, with a HR of ca. 600, has a lifespan of less than 2 years, the horse (HR ca. 40), lives ca. 40 years, the whale (HR less than 20) lives ca. 60 years. This same pattern is true for humans (RHR 72), but we live longer thanks to our intelligence and adaptability, with better protection and control of our environment and predators, better hygiene, prevention and control of infections and chronic diseases. Many of the known risk factors (in the FRS, INTERHEART, QRISK2), like smoking, stress, deprivation, obesity, sedentarism, diabetes, alcohol excess, atrial fibrillation, and rheumatoid arthritis, have an influence in the RHR. Sleep apnea, which is highly prevalent in patients with established cardiovascular diseases, hypertension, coronary artery disease, stroke, and atrial fibrillation, is common in obese persons, and they also have elevated RHR (Virend K. Somers et. al. AHA Scientific Statement. Circulation, Sept. 2, 2008) Last year, the ESC guidelines for the management of arterial hypertension (EHJ June 2007), mention that there is a growing body of evidence to include the elevated RHR as a risk factor for cardiovascular morbidity and mortality, as well as for all cause mortality. The very recent publication of the trials BEAUTIFUL, with ivabradine, and EUROPA, with Perindopril (Fox K. et al. Lancet 31 August 2008. Ferrari R. ESC Congress 2008, Munich), confirm the importance of a RHR over 70 or 75 bpm as a risk factor. The HR reducing Betablockers, that decades ago were contraindicated in Heart Failure, are now first choice. They improve the prognosis, even in the older patients, as demonstrated by the study SENIORS with Nebivolol, among other studies. Almost a decade ago (Sánchez-Delgado E. and Liechti H. Lancet 13 March 1999), we published our findings using the Pulse by Mass Index for a simple, rapid and individualized risk evaluation. We proposed that all persons older than 30 years with the following clinical factors should be screened: overweight (body mass index [BMI] over 27 kg/m2 ), a RHR (pulse) over 85 per min, or a Pulse by Mass Index over 1·0, calculated with the formula: Pulse or RHR multiplied by the BMI and divided by 1730 (the common denominator RHR 72 × BMI 24) We compared prospectively, in a preliminary group of 20 patients the Pulse by Mass index with the Framingham Risk Score. The correlation was highly significant (r=0·94; p<0·05), especially in patients over 40 years, despite the Pulse by Mass index being more sensitive for younger patients. Most patients with a Pulse by Mass Index of 1.3 or more will probably have a high global cardiovascular risk when calculated by the Framingham Risk Score. In the meantime, we have validated the Pulse by Mass Index and its prediction potential in over 1650 patients. We also compared caloric intake with life expectancy in the 20 most developed countries and found that, indeed, an ingestion of 280 kcal less every day corresponds to 25 months longer lifespan. These findings probably indicate the relation between hyperinsulinemia, stimulation of the sympathetic nervous system, and oxidative metabolism that is seen in obese patients and which improves when they exercise regularly or lose weight. Caloric restriction has consistently increased the lifespan in all species studied. People that expend 2000 calories a week in exercise, live longer. That is approximately 280 calories a day. We correlated Pulse with BMI, because the RHR reflects the oxidative metabolic rate and activity of the sympathetic nervous system, such as under stress, obesity or hyperinsulinemia. More recently, Julia Hippisley-Cox et. al. in the QRISK2, (BMJ 28 June 2008) use 14 risk factors to predict the cardiovascular risk. Of them, Body Mass Index, as well as those that can have an influence in the resting heart rate, like smoking, deprivation, atrial fibrillation, type 2 diabetes and rheumatoid arthritis, are in fully agreement with our findings. The importance of the Body Mass Index in the risk assessment becomes thus supported both by Hippisley-Cox et. al. as well as also recently by the Framingham Heart Study that incorporate the BMI in their new tables (Circulation 12 February 2008). Similarly, the Framingham Offspring Study (Wilson PW, et al. Circulation 2008, July 8), in a simple prediction model of CVD that included age, sex, and smoking, found that 1-SD unit (4.33 kg/m2) of BMI imparted a 28% effect on risk of initial CVD events. It was estimated that 67% of the BMI effects appear to operate through the ratio of cholesterol to high-density lipoprotein cholesterol, systolic blood pressure, and diabetes mellitus. Recently the BMJ (Minerva, BMJ 5 August 2008) comments that Body mass index can be added to the list of traditional cardiovascular risk factors (high systolic blood pressure, higher ratio of cholesterol to high density lipoprotein cholesterol, and diabetes) for predicting first coronary heart disease events. These new studies support the clinical value of the Pulse by Mass Index for a rapid, inexpensive, individualized, and non-technologically demanding assessment for the prevention strategies of the individual patient, as well as for epidemiological studies, in view that around 80% of all cardiovascular deaths occurs in developing countries. The practical advantage of the Pulse by Mass Index should be of more extensive clinical use worldwide. The Pulse by Mass Index is also useful for the elaboration of the prevention strategies and for the consideration and prediction of potential adverse reactions of cardiovascular and metabolic drugs, as we also could see and published a decade ago (E. Sánchez-Delgado. Intercontinental Cardiology, May 1999). The findings of recent studies, like ACCORD, ADVANCE, and DIGAMI 2, are in concordance with the fact that the effects of drugs on the body weight or on the RHR (like in case of hypoglycemia), are determinant for their benefits or harm. Prof. Enrique Sánchez-Delgado, MD Competing interests: None declared |
|||