Ask The Doctors: August 2017
Q: I’m 71 with a small abdominal aortic aneurysm that is monitored regularly. It has grown slightly in the past year, but not to the point where my doctor feels we need to do anything. Do small (almost 4 cm) aneurysms ever rupture? What size needs surgery to repair? Would it make sense to treat it now before it becomes more dangerous?
A: Abdominal aortic aneurysms (AAAs) can grow in size over time, leading to symptoms, and if they get too large, rupture causing life-threatening bleeding or death. Most are found incidentally, and if small, watchful waiting is appropriate. Diameter is the best predictor of rupture. Aneurysms of 3 to 4 centimeters (cm) should be checked yearly with ultrasound or CT, and if above four cm, or with rapid change in size, more frequently. Those above 4.5 cm should be evaluated by a vascular specialist/surgeon.
Yearly rupture risk is zero percent at less than four cm, increasing to 3 to 5 percent when greater than five to six cm. Generally an asymptomatic aneurysm of over five to 5.5 cm (1.9 to 2.2 inches) should undergo repair. A smaller size may be appropriate for repair depending on body stature, gender, symptoms, or rate of change in size. Expansion of more than 0.6 cm per year is also considered high risk for rupture. The decision to repair an AAA requires a balance of risk of rupture, risk of surgery and life expectancy. An open surgical procedure with a synthetic graft, an endovascular repair with a stent-graft placed via catheter or a combination may be used. Since surgical procedures are not without risk, a watch-and-wait approach until the aneurysm is of sufficient size makes the most sense.
In your case the best approach would be to reduce the expansion rate and rupture risk with a heart-healthy diet, not smoking, regular exercise, and treatment of high cholesterol and blood pressure. Any new sudden pain in the abdomen, back or spreading to the leg, nausea, dizziness, or sudden increase in heart rate may be a warning sign of rupture, and rapid medical attention should be pursued.
Q: I have had stable angina for about three years. I know how much exercise I can do before I feel any chest pain. My numbers (blood pressure, cholesterol, etc.) are pretty well controlled. Is there any way to predict if I’ll eventually develop unstable angina, and can I do anything to help prevent that?
A: Unstable coronary syndromes, including heart attack and unstable angina, are due to a combination of vulnerable atherosclerotic plaque and blood clotting. When a coronary artery plaque ruptures or fissures, the stage is set for accumulation of platelets at that site and clot formation leading to occlusion or partial occlusion of the artery and consequent heart attack or unstable angina. Individuals can have chronic angina due to a stable narrowing of a heart artery and never progress to unstable syndromes. Conversely, an individual may have an obstruction that is not severe enough to cause symptoms, but an acute event may occur suddenly if a less stable plaque becomes disrupted and clots. The best way to help plaques become more stable and less inflamed and to prevent blood clotting is with a combination of medications and lifestyle initiatives. Statin medications not only reduce cholesterol but also have plaque stabilizing benefits. Blood pressure control to reduce shear forces in the arteries and aspirin to prevent early clot formation are important. Maintaining normal weight, a diet such as a Mediterranean diet, and regular exercise are also helpful. It is important to be attentive to any changes in angina frequency or symptoms provoked at lower activity levels. A change in pattern may be an early sign of plaque instability requiring prompt medical attention to prevent progression to heart attack. Even if your angina pattern is very stable, you may have improvement in symptom thresholds with medication and exercise training.