Tuesday, May 24, 2011

Physician Interview: Prevalence of heart disease in black community

View the full video interview on Rouge Valley’s YouTube channel.

Cardiologist Dr. Paul Galiwango is the medical manager of cardiac imaging at Rouge Valley Health System (RVHS). Here he discusses his particular interest and insights on the issue of heart disease and hypertension faced by the black community.

Q: What is hypertension?
A: Hypertension is high blood pressure. The heart pumps blood into vessels; and if the pressure is too high, the heart has to work harder to pump blood. Over the long term, it leads to damage of the lining of the vessels, and increases the chances of blood clots, strokes, and blood vessels bursting. There are usually no symptoms, which is why it’s important for patients to visit their physician regularly, so that we can try to detect it at that silent stage—before it wreaks any damage.

Q: Why are blacks more susceptible to hypertension, heart failure and stroke?
A: We certainly know that hypertension affects the black community more disproportionately. We see an increase in frequency, and we see it at younger ages. In addition to that, hypertension is often more resistant to treatment on patients in the black community. And it seems to have a particularly malignant vascular effect in terms of organ damage to the heart, kidneys, and brain. Why we see that is still a subject of fierce debate. I think it is multi-factorial. There are some genetic studies that suggest  there are some unique aspects in the way the kidneys handle the sodium load, which makes blacks more sensitive to salt. And salt affects the cause of high blood pressure—so we call it sodium-sensitive hypertension. And then there are also some lifestyle issues. For example, if you look to the American south, there tend to be some very high-sodium diets, and high prevalence of obesity. So this also contributes to the hypertension rates.

Q: Why do stroke and heart failure tend to present so young in blacks?
A: It certainly seems to be linked to the prevalence of hypertension coming at a younger age. There was a large study that came out last year that looked at a very diverse group–whites, blacks, Hispanics–and followed them for 20 years. What they found was the prevalence of heart failure at a young age (younger than 50 years old) was about 20 times higher in blacks than in the non-black participants. And the lion’s share of that contributed to hypertension. Researchers saw that for every 10 millimetre increase in blood pressure in a black person in their 20s, you double the risk for heart failure in their 40s.  It’s sobering, but what’s encouraging is that it’s a treatable condition.

Q: When you see black patients, how do you treat them? What sort of programs do you put them on? Is it particularly unique?
A: In any patient who I see with hypertension, I treat aggressively. Hypertension is silent, and it’s easy for it to progress without the patient even realizing it. With black patients, there are some nuances—we do know that they respond differently to certain classes of drugs that are commonly used for hypertension, like ACE Inhibitors, Beta Blockers. Data has suggested that medications such as these may be less effective in the black population. So I would tend to stay away from those, at least at first, and go to more effective drugs like Calcium Channel Blockers and Diacide Diuretics.
    I also really underscore the importance for everyone—particularly in the black population—of trying to avoid salt in their diet. People often recoil at that suggestion at first, but you do find that with time, the palate adapts, and you get used to it. There’s just so much sodium already in packaged foods, it’s best to try and cut out salt anywhere you can. I recommend just not adding it to table food, or when you’re cooking. In fact, I’ve learned to cut salt out of my own diet.

Q: What do we do at Rouge Valley to treat this population?
A: The cardiologists at Rouge Valley are all very cognizant of these issues, and can aggressively manage heart hypertension in all patients, and know what to do when they see anyone approach. We have a very diverse community in Toronto and Durham—blacks, South Asians, Asians, etc.—so we deal with everyone appropriately. But I’d also emphasize that the cardiac rehab program is an excellent one, and it gives all the patients the tools they need to live a healthier lifestyle—and aids in helping them to abandon some of the more harmful habits, like smoking, or a high-sodium diet. So we also refer a lot of our patients to that program.
    It’s important for physicians who are treating black patients whose hypertension has gotten quite difficult to treat, not to give up and refer those patients on to a specialist for evaluation. It’s possible that the medication might need to be tweaked, or replaced. A lot of times, it’s a bit frustrating to have a patient on medication for a while, and their blood pressure isn’t coming down. But if that’s the case, they really should be referred on. You can get there, but you just have to persist.

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