When it comes to treating blocked coronary arteries, the two major options–coronary artery bypass surgery and coronary artery stenting–have traditionally been in competition. And conventional wisdom held that endovascular coronary artery interventions keeps getting better, with improved stents, while surgical bypass remains fairly stable. After all, surgery is surgery, right?
Well, the simple answer is: Wrong! Surgery has gotten better, too, even over the past decade.
Earlier this month, at the annual meeting of the American Association for Thoracic Surgery,
I heard some startling statistics on how much cardiac bypass surgery progressed during the 2000s, numbers that bear repeating and even celebrating.
A report by Andrew W. ElBardissi, a cardiac surgeon at Brigham and Women’s Hospital in Boston, used data collected by the Society of Thoracic Surgeons on U.S. coronary bypass surgeries done in 2000 and in 2009.
In 2000, more than 136,000 U.S. patients underwent bypass surgery. During the 30 days following surgery, their mortality rate was 2.4%, and 1.6% had a stroke. In 2009, more than 160,000 U.S. patients underwent bypass surgery, with a 30-day mortality of 1.9% and a 1.2% stroke rate.
These changes may sound small, a 0.5% drop in mortality and a 0.4% fall in stroke rate, but in addition to being statistically significant these decreases meant better outcomes for hundreds of patients each year.
With more than 160,000 patients having coronary bypass surgery in 2009, the improvement over the course of 10 years meant that in 2009, 800 fewer patients died following surgery and 640 fewer patients had a stroke compared with the rate 10 years earlier. Well over a thousand patients had a substantially better outcome from their surgery a decade later because of improvements in surgical technique and patient management. Presumably the numbers were at least as good last year, too, as well as today, next year, and beyond.
These improved outcomes are actually even better because other parts of Dr. ElBardissi’s analysis showed that 2009 patients were sicker than coronary bypass patients treated a decade before. Elective cases fell from 58% of all surgeries in 2000 to 41% in 2009. Balancing this shift was a sharp rise in urgent surgical cases, which jumped from 38% of all bypass cases in 2000 to 54% in 2009. Another measure of how the cases grew more complex was the percent of patients who underwent bypass of their left main coronary artery, the coronary procedure that is riskiest because the left main artery is so critical for supplying blood to heart muscle. Left main bypasses jumped from 23% of the coronary surgery cases in 2000 to 32% in 2009. The 2009 patients also had substantial rises in the prevalence of hypertension, hypercholesterolemia, and chronic obstructive pulmonary disease.
Why did bypass surgery do so much better in 2009, even as patients got sicker? Dr. ElBardissi’s data provide a few likely explanations: In 2009, use of internal mammary artery grafts–the optimal graft vessel–rose from 84% of cases in 2000 to 95% of cases in 2009. And use of helpful medications, including beta blockers, aspirin, and statins, all rose from 2000 to 2009.
—Mitchel Zoler (on Twitter @mitchelzoler)