Coronary Artery Disease: Stent or Surgery?

The results of an international study comparing surgical bypass of multiple diseased coronary arteries with minimally invasive angioplasty and coronary artery stenting is reported in this week’s issue of the journal Lancet.  The Stent or Surgery (SoS) trial involved 53 hospitals throughout Europe and Canada, and randomized 500 patients with multiple vessel coronary artery disease to coronary artery bypass surgery (CABG), and 488 patients to percutaneous transluminal coronary angioplasty with coronary artery stenting (PTCA-CAS).  CABG requires general anesthesia, surgical entry into the chest, and the use of a heart bypass pump.  PTCA-CAS, on the other hand, is performed using local anesthesia and mild sedation, and involves the passage of a special catheter through an artery in the thigh or upper arm.  During a CABG operation, the surgeon uses arteries in the chest or/and veins in the legs to bypass the clogged segments of the coronary arteries altogether.  PTCA-CAS, on the other hand, employs a tiny expandable balloon to expand the narrowed coronary arteries.  An expandable metallic stent is then left behind within the interior of the coronary arteries to help maintain patency.  This study was performed because earlier studies of PTCA alone were associated with a high risk of recurrent narrowing (stenosis) of coronary arteries following angioplasty.

All patients in this study were followed for at least one year after undergoing either PTCA-CAS or CABG, with more than half of the patients receiving follow-up for two or more years.  The researchers in this study found that 21% of the patients who underwent PTCA-CAS required subsequent repeat procedures for restenosis of the coronary arteries during this relatively brief follow-up period, while the patients who received CABG required revascularization procedures in 6% of cases.  There was also a modest but significant difference in the likelihood of death between the two patient groups.  Among the PTCA-CAS group, 5% of patients died during the study, while only 2% of the CABG patients died. 

The authors concluded that the addition of coronary artery stenting to PTCA reduces the need for coronary artery revascularization when compared to results obtained in previous studies looking at PTCA alone.  However, patients with multiple diseased coronary arteries who undergo PTCA-CAS still appear to have a higher incidence of requiring additional procedures to revascularize restenosed coronary arteries than similar patients who are treated with CABG.  The study also identified a nearly three-fold increase in the risk of dying among the PTCA-CAS patients when compared to the CABG patients.  While nobody looks forward to having their chest cracked open, their heart stopped, and their coronary arteries bypassed, it appears that CABG remains a superior treatment for patients with coronary artery disease involving multiple vessels.  As the technology for preventing restenosis following coronary artery stenting continues to improve, I predict that the time will come when PTCA-CAS will be as effective and as durable as CABG (if not more so).  At the same time, recent advances in minimally invasive CABG on the beating heart, and without need for a heart bypass machine, may continue to tip the scale in favor of CABG some time to come.

Best Way to Diagnose Appendicitis?

For centuries, surgeons have debated the most accurate methods for making the clinical diagnosis of appendicitis.  Classical surgical texts describe the onset of appendicitis heralding with vague periumbilical pain which then, at some later point, begins to migrate or localize towards the right lower area of the abdomen.  The trouble with this scenario is two-fold.  First of all, other disease processes within the abdomen can cause nearly identical symptoms.  For example, swelling of the lymph nodes near the appendix after a viral or bacterial infection is a notorious and common cause of “pseudoappendicitis.”  Secondly, the inflamed appendix, it would appear, doesn’t always read the classical surgical texts regarding how it should behave.  Patients with bona fide appendicitis may present with many variations in the location, timing, severity and quality of their pain, and may present with other symptoms as well, making the diagnosis even more challenging.  Over the past 5 years, ultrasound and CT scans have been touted by some experts as valuable aids in making—or excluding—the diagnosis of appendicitis.  Proponents of this expensive high tech approach cite the 10-15% incidence of a normal appendix among male patients undergoing appendectomy when clinical diagnosis alone was used.  Women patients fare even worse when the surgeon relies upon clinical considerations alone, with some studies reporting a 40-50% incidence of an unremarkable appendix at the time of surgery.  On the other hand, since so many patients with suspected appendicitis will ultimately prove to have some other condition (and, often, a condition that does not require surgery), opponents of the routine use of ultrasound or CT scanning claim that too many scarce and expensive resources will be wasted on too many patients.

In this week’s journal Gastroenterology, 350 consecutive patients who presented to the emergency room with suspected appendicitis participated in a research study that was designed to resolve this ongoing controversy.  All participating patients were categorized according to the surgeons’ degree of clinical suspicion for a diagnosis of appendicitis.  All patients then underwent ultrasound evaluation of their abdomen by a radiologist.  As a surgeon, it pains me somewhat to see that, according to this study, the radiologists fared quite a bit better than their surgeon colleagues.  Among the patients deemed to be at low clinical risk of having appendicitis, 10% actually did have the disease.  Among the intermediate clinical probability group of patients, 24% had a hot appendix.  Within the group of patients that the surgeons were most convinced of the diagnosis of appendicitis, only 65% of the patients actually had an inflamed appendix, while 18% had some other identifiable cause for their belly pain, and 17% were never found to have any abnormal conditions.  Using ultrasound, the radiologists were able to accurately make the diagnosis of appendicitis in 98% of the patients who actually ended up having the disease, and incorrectly made a diagnosis of appendicitis in only 2% of the patients who turned out to have a normal appendix, for an overall diagnostic accuracy of 98%!  These are pretty impressive numbers, and so, at least based upon this study, the radiologists appear to have scored better in making an accurate preoperative diagnosis when compared to the surgeons.  I will add two caveats, however.  Firstly, performing a high quality ultrasound scan is a subjective and complex process, and it really does take a very skilled and experienced radiologist to reproduce the level of diagnostic accuracy achieved in this study.  Secondly, many hospitals not only do not have radiologists with a lot of experience in making diagnosing appendicitis with ultrasound, but finding such a rare creature late at night in the hospital (i.e., when patients are rolling into the ER because their abdominal pain is keeping them awake) is often an impossible task.  Still… I have to hand it to the radiologists participating in this study, as their results are very impressive.

Antioxidants & the Risk of Stomach Cancer

The proper role, if any, of dietary antioxidant nutrients in the prevention of cancer is a hotly debated subject.  There are numerous studies showing either a reduction in the incidence of cancer with an antioxidant-rich diet or no change in the incidence of cancer.  There is even a study that revealed an apparent increase in the risk of lung cancer among smokers who also took beta carotene supplements.  Now, a new study in Gastroenterology takes a look at the effects of dietary antioxidants on the risk of stomach cancer.  A total of 505 patients with newly diagnosed gastric cancer, and 1,116 “control patients” without cancer, were enrolled into this study.  All participating patients were then carefully interviewed to ascertain their dietary habits. The researchers then calculated the antioxidant potential of each patient’s diet based upon the content of specific vegetables and fruits that they commonly consumed.  Briefly, the study showed that patients with the highest intakes of antioxidant-rich plant-based foods, overall, had a 35% lower incidence of stomach cancer than patients with low levels of antioxidant-rich diets.  When the incidence of smoking among the two groups was accounted for, the inverse relationship between dietary antioxidants and the risk of gastric cancer became even more pronounced.  Patients who had never smoked and who had the highest levels of antioxidants in their diet had a 56% lower risk of gastric cancer when compared to the other study patients.

While dietary survey studies are somewhat subjective by their nature (as they rely upon the memory and honesty of the test subjects), they are still powerful tools for assessing the impact of dietary factors upon the development of diseases that may be linked with eating and drinking habits.  One can, therefore, infer from this study that a diet rich in antioxidants may be associated with a reduced risk of developing stomach cancer and that smoking, particularly in the presence of low levels of antioxidants in the diet, may increase the risk of gastric cancer.