Coronary Angiography: Title and subTitle BreakA Long Look at a Short Queue

Over the past 2 decades there has been an exponential increase in the use of all cardiovascular diagnostic and therapeutic procedures, especially coronary angiography. Indeed, heart catheterization is now the most frequently performed in-hospital operative procedure in patients older than 65 years.¹ Researchers estimate that during 1995 more than 1.6 million patients underwent heart catheterization in the United States and that by 2010, upward of 3 million cardiac catheterizations will be performed annually.¹

In this issue of THE JOURNAL, Rosanio and colleagues² examine outcomes of 381 patients who were referred to a public hospital in Galveston, Tex, for elective coronary angiography but were forced into a queue. Patients with recent myocardial infarction and class IV angina were taken to angiography and excluded from the study. The authors found that after a mean follow-up of 8.4 months, 283 patients (91%) had uneventful waits. However, after 3 weeks the longer patients were in a queue, the greater the likelihood of some adverse outcome. Rosanio and colleagues identified risk factors for patients who should not wait for angiography and suggest that it "is likely that a sizeable portion of the US population may experience difficulty in accessing health care and delays in receiving medical services."

Rosanio et al report a local experience, and it is unclear whether the findings can be generalized to the hundreds of thousands of patients with coronary artery disease deemed suitable by their physicians for coronary angiography. Given this large pool of patients and the remuneration associated with this procedure, administrators and cardiologists from hospitals of all sizes are pressing for certificates of need to open laboratories for coronary angiography and angioplasty and to establish programs for open heart surgery. In view of this, it is unlikely that there are many queues for these procedures. The authors do not explain whether patients in the Galveston queue could have been referred to other facilities in the area. Moreover, Rosanio et al² raise some specific concerns about populations of individuals who are uninsured or underinsured, as well as the role of race and sex, which affect referral patterns for interventional cardiovascular procedures.³ That notwithstanding, the growth of invasive cardiac procedures is attributable to several nonclinical factors that were detailed a decade ago⁴ : economics, overtraining of interventional cardiologists, fear and anxiety by patients and their families of imminent sudden demise, conflicts of interest between individuals and groups carrying out research in various areas, and the need of interventional cardiologists to perform a minimum number of procedures to maintain subspecialty certification. One could argue that the problem in the United States is that there are too many and not too few cardiac catheterization laboratories.

Powerful economic forces continue to "drive the train" in the provision of medical care. Business strategies to improve the financial bottom line in the health care "industry" have become more pervasive and aggressive. Were it not that the fiscal survival of many hospitals depends on the ability to carry out high-reimbursement procedures, physicians and other health care professionals might not have entered a time in which the currency of the realm is patient volume and patients are referred to as "market shares." In this situation, coronary angiography has become the conduit to coronary angioplasty or coronary bypass graft surgery.

Rosanio et al² found that among patients who waited for angiography the likelihood of occurrence of adverse clinical end points increased between weeks 3 and 13. The authors also found that strongly positive treadmill stress tests and a history of use of 2 to 3 anti-ischemic medications were factors that would indicate early intervention. Thompson et al⁵ found that irrespective of the degree of ST-segment depression during exercise testing, stabilization of symptoms while taking multiple anti-ischemic medications and time on the treadmill of 9 minutes or longer render a patient at low risk for cardiac events.

Indeed, it is worth asking whether the anxiety and other concerns induced by explaining to patients why they require coronary angiography become a self-fulfilling prophecy as the patient nervously awaits the intervention. Thus, obtaining fully informed consent for the procedures may present a complicated ethical and moral dilemma. How many clinicians, in securing consent for catheterization, angioplasty, or both directly state the risks of a cerebrovascular event, myocardial infarction, or even death, as well as a number of lesser morbidities that may occur as a result of the initial and any subsequent procedures?

For the patient with stable symptoms, adequate ventricular function, and acceptable hemodynamics during exercise testing there appears to be no advantage in performing aggressive interventional procedures.⁶ One reason that the threshold for recommending coronary angiography is constantly being lowered may relate to the excess number of interventional cardiologists, all of whom are expected to fulfill a minimum number of cases as the first operator. The rationalization for subjecting patients to the cascade of procedures that may be advised following coronary angiography is in part based on "quality of life,"⁷ a dubious claim in a large percentage of patients.

An increasing body of data supports a noninterventional approach to the management of stable coronary artery disease. Two studies by Hueb and colleagues^{8 - 9} are germane. The initial study examined survival rates in 150 patients with multivessel disease who refused coronary bypass graft surgery. Annualized mortality was 1.3% for 3-vessel or "left main" equivalent coronary disease.⁸ A subsequent study was a prospective trial comparing outcomes in patients with single-vessel, left anterior descending coronary disease randomized to either medical therapy, angioplasty, or bypass surgery. There was no difference in rates of mortality or nonfatal acute myocardial infarction among patients with left anterior descending disease who underwent surgery or angioplasty, or received medical therapy.⁹ Experience at our center suggests that the majority of patients referred for coronary angiography with stable symptoms and normal ventricular function experience a similar 1% per year mortality during a nearly 4-year follow-up.¹⁰ In the coronary angioplasty vs medical therapy for angina (RITA-II) trial,¹¹ during which a thousand patients with stable angina were randomly assigned to receive either medical therapy or invasive intervention, the combined rates of death or definite myocardial infarction were 6.3% for patients undergoing angioplasty vs 3.3% for patients receiving medical therapy.

Delays for intervention in a patient with unstable symptoms are unconscionable given the high risk and the ready availability of cardiac catheterization laboratory services. One might infer from the explosion in the use of coronary angiography that the majority of patients undergoing the procedure are asymptomatic or minimally symptomatic. Their clinical status is stable, but by virtue of a "failed" exercise treadmill test or imaging study the patients are advised to undergo one of several procedures that might result in unforeseen morbidity or death. This is equally unconscionable.

Rosanio et al² conclude that appropriately selected patients who have to wait for coronary angiography may be at a small but finite risk for an adverse cardiac event. The likelihood, however, of a need for a queue for angiography in the United States in 1999 is remote given the abundance of facilities and interventionalists. However, for all patients for whom coronary angiography is being considered, it is incubent that patients' interests be paramount and override any self-interest of the facility or interventionalist.