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Commentary Response: Primary Angioplasty is Now the Benchmark for the Treatment of AMI and Needs Broader Access
Primary PTCA vs. Fibrinolytic Therapy Dr. Ryan™s contention that there is no conclusive evidence that primary PTCA is superior to fibrinolytic therapy in acute myocardial infarction (AMI) is counter to a large volume of literature1-4 (see also Table 1 and Figure 2 of our article). More recent evidence includes the randomized STOP AMI study5, which found that primary PTCA with stents and abciximab yielded dramatically superior outcomes in patients with AMI compared to alteplase, and the just-announced randomized C-PORT trial at community hospitals without on-site cardiac surgery, which we will describe below. Despite these randomized trials, Dr. Ryan cites three registries to support his position that randomized trial outcomes are not reproducible in the community. Yet Dr. Ryan does not cite another more recent report of a registry of 2,291 patients from New York state.6 This registry demonstrated outstanding outcomes for primary PTCA outcomes that did in fact reproduce the trial results. In this paper, Drs. Hannan, Ryan, and colleagues concluded that the mortality rates reported in our study are, for the most part, similar to those reported by other studies in the literature¦Furthermore, the mortality rates reported in this study for primary angioplasty are lower than the rates reported for thrombolytic therapy in recent studies. For these reasons, primary PTCA is becoming first-line care at more and more hospitals throughout the country, with Boston University being a notable member of this group. (See also Figure 7 of our article.) Despite Dr. Ryan™s complaint about our certainty of it all, we in fact do not claim certainty for the superiority of primary PTCA over lytic therapy at all hospitals and by all operators. But even if one assumes that the therapies were merely equal at qualified centers, we pointed out that primary PTCA may yield better outcomes than conservative therapy in the large subgroups of patients with AMI that are not appropriate for lytic therapy (which, in fact, comprise the majority), and thus can be much more broadly utilized as a reperfusion modality at qualified hospitals7-14 (see also Tables 4 and 5 from our article). Fibrinolytic-Ineligible Patients A few comments are in order with regard to certain lytic-ineligible subgroups. For example, we advocated an aggressive approach in patients with ongoing uncontrolled chest pain and non-ST-elevation AMI.15 We are puzzled why Dr. Ryan does not seem to endorse this approach, since both the revised ACC/AHA guidelines for AMI16 and the new ACC/AHA guidelines for acute coronary syndromes17 clearly recommend this approach as a Class I indication for such patients with uncontrolled symptoms. We are equally puzzled why he doesn™t seem to support an aggressive approach in the elderly, since a recent review of Medicare data indicates than in patients over 75 years old (perhaps one-third of all patients with AMI), lytic therapy may yield worse outcomes than no reperfusion therapy, especially in women.10,11 Another study demonstrates that primary PTCA improves mortality dramatically compared to lytic therapy in elderly patient.18 It is true that the current ACC/AHA guidelines for AMI do not yet specifically classify the indication category for primary PTCA by high-volume operators at non-surgical hospitals in patients who are lytic-ineligible or in shock (shock is otherwise a Class I indication), but rather simply state that PTCA should not be done by low-volume operators in lytic-eligible patients at such hospitals.16 We continue to assert the superiority of the aggressive approach in patients with AMI. This assertion is given additional weight by the just-announced results of the TACTICS trial, led by Dr. Christopher Cannon of Brigham & Women™s Hospital, Boston, which convincingly proves the superiority of an early aggressive approach in patients with other high-risk acute coronary syndromes.19 Increasing the Availability of Primary PTCA Clearly, if a certain therapeutic approach is superior in a life-threatening disease, the appropriate response is to explore ways to make this approach more widely available. In our article, we presented an examination of the latest outcomes data for primary PTCA when performed at hospitals without on-site surgical back-up. We cited a cumulative experience in the literature of over 1,600 primary PTCA procedures at hospitals without surgical backup, and over 70,000 PTCA procedures in Europe. We believe this extensive accumulation of outcomes from the US and abroad, and the new results of the C-PORT trial which we will discuss below, begs Dr. Paolo Angelini™s question, Hasn™t coronary angioplasty finally gained sufficient technological maturity and professional confidence to be self-reliant and free-standing?20 Early Aggressive Management of Cardiogenic Shock Dr. Ryan states that cardiogenic shock should be treated at surgical centers, since 40% of patients in cardiogenic shock require revascularization by CABG. In fact, only 15% of 884 patients in the SHOCK registry received CABG21 and only 36% of 152 patients in the revascularization arm of the randomized trial received CABG as the first revascularization attempt22, a net of 18% of 1,036 patients (excluding of course those randomized to the medical therapy arm). In this SHOCK trial, randomization within 6 hours of onset of symptoms conferred the greatest survival advantage of all descriptors. Another recently reported large series by Dr. Bruce Brodie and colleagues confirms this crucial importance of time-to-treatment for survival in shock, with dramatically increased survival in patients receiving PTCA within the first 2 hours.23 It is difficult to stabilize shock patients and transfer them to a surgical center for an intra-aortic balloon pump (IABP) and PTCA within these short time frames. Surgery, when performed for shock, is often performed after IABP and further stabilization, and often after PTCA recanalization of the culprit lesion. It is a far more attractive option to offer IABP and PTCA at the point of first contact before transfer with an open vessel and balloon pump than it is to delay PTCA in favor of transfer before cath solely to provide access to a procedure (CABG) that will usually be deferred for PTCAif it is utilized at all. Practical and Logistical Considerations Dr. Ryan speaks of the expense involved and of the experience required in setting up primary PTCA programs. We do not advocate the building of new cath labs and the hiring of new personnel merely to provide primary PTCA, but rather we advocate extending the capability of certain qualified existing diagnostic laboratories that have experienced interventionalists. Such laboratories usually have an established on-call system. Interventional equipment can be obtained on consignment without extensive investment. Cath lab staff, if without previous interventional experience, can be trained in intervention at the supporting surgical hospital, as Dr. Tom Aversano of the C-PORT trial and others have demonstrated so well. In addition, as Dr. Aversano points out, Community hospital CCU physicians and nursing staff are already experts in the care of AMI patients.24 He adds, These, of course, are the very hospitals to which at least 2/3 of patients with acute MI present.25 Volume Considerations Dr. Ryan takes exception to our assertion that almost all non-surgical hospitals that provide primary PTCA as first-line therapy perform well over 36 procedures annually something that both we and Dr. Aversano recommend. Through our personal communication with over 60 U.S. hospitals that perform primary PTCA as routine AMI care, we reaffirm this assertion. Hospitals that are busy enough to support a cardiac cath lab and offer primary PTCA routinely on a 24/7 basis to a significant proportion of patients should be able to readily exceed this number. The C-PORT Trial Exciting new data on the efficacy and safety of primary PTCA without cardiac surgery has just been presented from the C-PORT randomized trial.24 This 453-patient trial, the second-largest of all prospective randomized trials to date of primary PTCA vs lytics in AMI, demonstrated the superiority of primary PTCA at hospitals without cardiac surgery provided they performed two or more procedures per month. Groups that particularly benefited were women, diabetics, and the elderly. No patient in this trial required emergency surgery for PTCA mishap. Dr. Tom Aversano, the C-PORT principal investigator, concluded that the need for in-house cardiac surgery backup is not supported by this data. We congratulate Dr. Aversano, the principal investigators, nurse coordinators and institutions that carried out this extremely important randomized trial. Standards-of-Care and State Regulations We are not sure why Dr. Ryan fears that we are advocating a new national standard-of-care of patients with acute MI. We certainly do not assert that every community hospital should gear up to perform primary PTCA. We, and many others including Dr. Aversano, agree that rigorous requirements must be met before any hospital, with or without cardiac surgery, can launch a safe and effective primary PTCA program (Tables 6 and 7). But qualified hospitals without cardiac surgery should no longer be prevented from doing so by statute. Dr. Aversano, discussing the implications of C-PORT in a recent press conference, also referred to this current paradox of the documented superiority of primary PTCA vs. the regulations that prohibit hospitals without cardiac surgery from performing the procedure. There are important regulatory barriers that continue to this day that inhibit access of most of the patients with acute myocardial infarction to primary angioplasty, and those regulatory barriers which are also in the ACC/AHA guidelines¦These, of course, are the very hospitals to which at least 2/3 of the patients with acute MI present.25 To reiterate Dr. Aversano™s conclusion regarding the C-PORT results: These findings do not support the requirement that smaller centers have in-house cardiac surgery backup.24 Basic Areas of Agreement: Are We Working Toward a Consensus? Notwithstanding our above differences, we are heartened that Dr. Ryan agrees that there are risk/benefit considerations that enter into the management of acute MI patients that would warrant the performance of Primary PCI in community hospitals without surgery on-site. We are also heartened by Dr. Ryan™s further conclusion that immediate coronary angiography with primary PTCA as the planned therapy if suitable, can be safe and effective in the management of acute myocardial infarction patients at select community hospitals without cardiac surgery. Though we fully concur with these conclusions of Dr. Ryan, we still fundamentally disagree with his last words in the commentary: The current national guidelines should remain substantively unchanged. We would note that Dr. Sidney Smith, the chair of the committee that is revising the 1993 ACC/AHA PTCA guidelines, said in a recent interview that he would be looking at the C-PORT data very carefully.26 We strongly urge that current standards and guidelines be modified on state and national levels to reflect the new reality that Dr. Ryan affirms, so that this benchmark therapy for AMI can be made more broadly available.
