Danielle Lee: Good evening Jacksonville and happy Saturday. I am Danielle Lee, welcome to The Conversation with
Dr. Ali Kasraeian. As always, you too can join The Conversation. Give us a call 3401045. Dr. Ali, how are you today?
Kasraeian: I am good. How are you?
Danielle Lee: I am great. It’s been a while, glad you’re here. It’s a full house in here today.
Kasraeian: It is a full house, it is a full house. We are going to be talking about an amazing, interesting and actually a topic that’s going to affect a lot of Americans. I’m excited everyone to join us today on The Conversation on this wonderful November day. In studios, Dr. Michael Koren, a wonderful friend to The Conversation. He is a cardiologist here in Jacksonville, Florida at the Apex Cardiovascular Group. He’s also very [inaudible 00:00:47] to today’s conversation. He is the President of the Northeast Florida Chapter of the American Heart Association.
He’s actually very, very innovative in the world of clinical research. He is the current President of the Academy of Physicians in Clinical Research, the CE of the Jacksonville Center for Clinical Research and the founder of the Encore Research Collaborative, which brings together multi-institutional group of researchers and research organizations here in the state of Florida to advance our knowledge of medicine. Not just in terms of cardiovascular disease, but disease in general. Thank you for joining us today.
Dr. Michael K: Thanks for inviting me.
Kasraeian: Today, we are going to talk about the new 2017 guideline for high blood pressure. This has a lot of people talking, and a lot of people are very excited about the implications, both in the positive and the negative. It maybe a little bit controversial. Basically, we’ve gone from a prior recommendation where blood pressure, diagnosis of hypertension or clinical blood pressure that you have to worry about and potentially get treated, was 140 systolically, which is the top number, over 90 diastolically, which is the lower number, to 130/80. What does that mean to our population at large here in the United States?
Dr. Michael K: It’s going to affect a lot more people there. As one gets older, your blood pressure naturally goes up. In fact, when you get to about 50 years old, about half of the US population has elevated blood pressure. Then by age 70, the vast majority of Americans have elevated blood pressure. By lowering the threshold to 130/80, we’re going to affect many, many more people. It’s now estimated that over 100 million Americans will be affected and will require some sort of treatment for hypertension.
Obviously the first line of therapy will continue to be diet and exercise. In most patients, that’s inadequate. Then, we have to go to drug therapy. The lowering of the guidelines, which I’m sure we’ll talk quite a bit about, was driven by a very important clinical trial that came out actually two years ago called the SPRINT Trial, which was sponsored by the US Government, and was a very, very impressive trial that shows that lower is better for people who are over age 50.
Kasraeian: This was a really interesting study. They looked at more than 9,000 men and women over the age of 50. They randomly assigned them to two different pathways for managing their blood pressure. That basically means that people didn’t know which direction they were going to go, and they were treated. These are people with a systolic blood pressure, which is the top number, of 130 or higher. They had one cardiovascular risk factor that was not diabetes but another factor. They were assigned to a group that was going to have a tighter blood pressure control, meaning that top number was going to be 120 or less, versus the other group that was going to have a blood pressure control that was going to be 140 or less.
What they found was very impressive, that when your blood pressure was tighter, the group that had the tighter blood pressure control of 120 or less, they had a 25% reduction in cardiovascular events. Meaning they had 25% less strokes, they had 25% less heart attacks, they had 25% congestive heart failure or their heart worked … They didn’t have a breakdown in their heart so it didn’t function properly. Most importantly, they had a 25% reduction in cardiovascular related deaths. That’s pretty impressive.
Dr. Michael K: Yeah, tremendously impressive. That was over 3.2 years. Actually, the study was stopped early. It was supposed to be a five year study, and they stopped it after 3.2 years because the difference in the outcomes in the groups were so profound.
Kasraeian: Why did it take so long before people were adopting this everyone that goes to their doctor, whose blood pressure was 130, 140, they began to increase their medications, they really pushed the active exercise and getting people off the couch, or improving diet and exercise, stopping smoking to get your blood pressure even better controlled when the data’s so impressive?
Dr. Michael K: It’s a great question. I’ll make a little joke. We say that when we get three physicians together, you’ll get four or five opinions. I think we’ve seen a little bit of that in this particular circumstance. You summarized the SPRINT Study really, really well. I’ll add a few little things. One, these are all …
Kasraeian: I mean if you want good summary of cardiovascular research, you do need a urologist in the group to put it all together. That’s usually the best way to get it together.
Dr. Michael K: You’re a master at getting the story together in a succinct way, so I think it was very, very well said. A couple of things just to add, just to … Because this is what it comes down to is a word that we use called the generalizability of the results. Any time we do a study, the question is does it apply to everybody who we treat that has a similar situation? This is where the controversy comes in, and I’ll give you some details in a second. You did summarize the study very, very well.
It was a tremendous study. The fact that it ended early is really very, very profound. The studies are put together with an estimate of how long it’s going to take to show a difference. It turns out the difference was shown much more quickly than we expected. That’s just tremendous.
Kasraeian: For our audience, what that means is usually when people design a study, especially a big study, especially one powered by the Government and for, I should say, funded by the Government, the statisticians come up with the amount of patients that are needed and the amount of time needed to follow up, so that the information and the data that you get in, so the points of study, are large enough so you can make an assessment and an analysis that would give you some information that actually makes sense and can be statistically powerful. Meaning that if it’s negative, that we don’t find the difference, versus if we do find a difference, like we found here, it’s not just related to chance.
If we had a study that we just did this study on the five people in this room today, it probably wouldn’t be that statistically powerful and it wouldn’t be powerful enough for us to go and generalize it to the entire population of the United States for us to begin changing … Everyone in the United States for changing their blood pressure management. When you have a big study like this and you follow it, when the study shows such consistency in its result, then you can get the power you need quicker. You don’t necessarily need to follow it as long. That’s how impressive this study was.
Dr. Michael K: Yeah. Getting to the point of generalizability, there were certain patients that were not included in the study, so diabetics actually were not included in the study. You had to have some cardiovascular risk, other than just high blood pressure, so typically people were a little bit older. The actual average age in the study was between 66 and 67 years old. You had to have either some evidence of heart disease or high cholesterol or some other risk factor. We were looking at people that had some baseline risk that maybe higher than the average person over age 50. That was an important part of the study.
Your point about the profound results is absolutely spot on, and was actually a 27% reduction in mortality in 3.2 years. The actual mortality benefit was a little bit more than the overall benefit of the study. That was tremendous. The controversy is about the way the blood pressure was measured. In this particular study, when people came into the clinical trial centers, there were 102 sites that were involved in the US and Puerto Rico. It turned out that they had a very specific way of measuring blood pressure
What would happen is people would come in. They’d get a little bit relaxed and they would use an automatic cuff to measure the blood pressure three times, separated by five minutes. The patients were encouraged to relax and take it easy. Some people were a little bit concerned about that, because the way we measure blood pressure in a doctor’s office is a little bit different. Most people will tell you that nowadays in the doctor’s office, there’s a rush. You go in, people take your blood pressure. Doctor’s busy, everybody’s busy. You may get five or 10 minutes with the physician, and you may only get one or two blood pressure readings. It turns out that often readings in that setting maybe higher than the readings in the setting that we saw in the SPRINT Study.
Kasraeian: You maybe stressed out and you may have the ever-popular, ever-referred to White Coat Syndrome, which may elevate your blood pressure. What is the White Coat Syndrome?
Dr. Michael K: White Coat Syndrome is just the way people respond to stressful circumstances. That when a physician takes a blood pressure, particularly if it’s a male physician taking the blood pressure of a female patient, the numbers tend to be higher than they would be otherwise. There’s actually been very nice studies that show that when a female nurse takes the blood pressure of a female patient, it tends to be lower than when a male physician takes that same blood pressure.
That gets to this concept of generalizability. In fact, the reason that they use the numbers 130/80, rather than 120/80 which is actually the results of the study, was to give the physician community a little bit of leeway, in terms of how they treat these things. Understanding that when we take blood pressure in the office, it maybe a little bit higher than what you’re getting under these circumstances. Plus not every physician’s office uses automated blood pressure cuffs. Typically, we use a mercury cuff and our ears rather than an automated system. We believe that the automated systems maybe a little bit lower than what we get when we actually use a mercury cuff.
Kasraeian: Which is more accurate?
Dr. Michael K: The gold standard is still considered a manometer that uses a mercury column with-