More Heart Attacks Diagnosed, but Lower Mortality Rate
One would think that with all the advances in drugs, diet advice, nutritional supplement support, and lifestyle changes being made that the rate of heart attacks would be dropping like a rock. Today, we have methods like heart scans and calcium scores to identify more at risk persons and lipoprotein blood testing to more accurately pinpoint causes of heart disease. With all this new technology, how is it possible that over the last several decades the incidence of heart attacks has remained somewhat constant?
A new analysis of the last 40 years of Framingham Heart Study data suggests the answers may lie in better detection of small heart attacks that used to go undiagnosed. A second finding of the study was the marked decline in mortality from heart attack. As might be expected, this was attributed to improved intervention (think angioplasty and stents) and secondary prevention. The analysis tracked 9,824 adults who had not yet had a heart attack when first enrolled in the study over a period beginning the late 1960s.
Roughly two-thirds of the heart attacks noted over the entire period were discovered via abnormal electrocardiograms, leaving one-third detected using the available biomarkers at the time. The study lends credence to the theory that as new and increasing sensitive biomarkers for heart attack are developed, we simply detect smaller and smaller heart attacks. In the 1960s, the tests of choice were not as sensitive to detecting heart muscle damage. With the advent of the troponin test in the 1990s, we now have an exquisitely sensitive method of detecting even minor heart damage due to coronary ischemia (poor blood flow to the heart muscle).
The big news from this study was the sharp decrease in acute heart attack mortality. The hazard ratio for death dropped from 0.83 in the 1970s to 0.35 in the 1990s. The speculation is that a there were a number of contributing factors. One would be better primary prevention. Improved methods of detecting early heart disease (heart scans, for example), better means of testing and detecting (like NMR Spectrospcopy) both old and newer heart disease causes (like Small LDL and Lipoprotein(a)) coupled with focused prevention program, smoking cessation, etc., means heart disease develops more slowly (or not at all) and is caught earlier. As mentioned previously, we also have faster and more effective ways to unblock arteries once a heart attack occurs.
The take-away concept here is that you cannot always accept a statistic at face value. While the incidence of new heart attacks remains steady, it is primarily because we are doing a better job of slowing down the rate of heart disease by detecting them early and saving lives when heart attacks occur. This does not mean that we do not have a long way to go. Traditional medicine is still slow in adopting primary prevention technology. Too many people are still developing heart disease and having needless heart attacks. This means each of us must continue to practice informed, self-directed healthcare.
Looking out for your heart health,