Friday, August 8, 2008

BLOCKAGES IN ARTERIES ARE BETTER LEFT ALONE! No need to bypass them or to open them up.

Whenever an angiography report reveals blockages in heart’s arteries, people are told to get them opened up with the help of balloon angioplasty or to get them bypassed surgically. Most patients never ask why. A few who do raise this question are told that they are under an imminent threat of a heart attack and death. It is a well-known fact now that heart attacks are caused when the blockages burst (plaque rupture). Conversely, as long as they don’t rupture, they are harmless. A lesser known but more interesting fact is that smaller, harmless looking blockages, which are many a times not even visible on angiograms and mostly less than 60% in size, are the ones which are most likely to rupture. Therefore, in most cases angiograms give misleading information: either it does not show up the dangerous blockage, or it shows a dangerous blockage to be rather safe because it is less than 60%. Blockages which are more than 60% in size are considered as dangerous enough to warrant some serious intervention such as bypass operation or balloon angioplasty. But the fact is that it takes many decades for a blockage to reach that size (60% or more) and in that much time a lot of calcium has got deposited in the fatty material and a lot of fibrous tissue has grown into it, making it a “stable lesion” not likely to rupture and therefore, comparatively safe. Few decades ago when we were not armed with the presently available powerful research data, angiography-angioplasty-bypass nexus made some sense. But it is amazing that it is still not only carrying on, but is flourishing and thriving. A close and hard look at this anomalous phenomenon is called for: very interesting results are assured.
Only a few research studies have shown a survival benefit with bypass surgery and angioplasty, and these were done in the seventies before the availability of modern medications. Even these few studies are suspect as to their reliability because the differences shown by them in morbidity and mortality data as compared to management of heart disease with conservative approach (medicines + dietary modifications+ life-style modifications + exercise; collectively called “Medical Management”), is not “statistically significant” i.e. the difference is not clear cut. Most talked about such research study is CASS (Coronary Artery Surgery Study), conducted between 1975 and 1979. It showed marginally better 5-year survival benefit, but the results were not “Statistically Significant” There is not a single research study available to-date, which shows a clear-cut advantage over medical management. A noteworthy point is that in the 70’s, we did not have powerful medications which we have today, i.e. ACE-I’s, ARB’s, selective & highly selective Beta-Blockers, Statins, Ezetimibe, Fenofibrate, Nicotinamide, Antiplatelet Aggregation agents, Antioxidants and much more effective medications for treating Diabetes Mellitus. In addition, since 1995, we have access to another USFDA approved non-invasive treatment modality called “External Counter Pulsation” (ECP), which, when combined with diligent “Medical Management” significantly improves the outcomes. In the list of indications for bypass surgery, there is only ONE clear-cut/ absolute indication given by the American Heart Association, Canadian Heart Association and other such respected bodies: significant and symptomatic Left Main Disease. All other indications are subject to “failure of medical management” or “refractory to medical management”. The implied meaning is that it is NOT proper/appropriate to suggest Bypass Surgery till such time that all non-surgical options have been exhausted. But ground reality is unfortunately very different: moment blockages are detected, patients are threatened, "You can have a massive heart attack and die at anytime unless you undergo immediate surgery!" Some people have started calling it “Medical Terrorism”.
The truth of the matter is that the most recent studies, involving now more than 41,000 patients, and population studies involving more than two million people, have shown that an alternative or alternatives to bypass surgery are associated with far lower morbidity and mortality. In other words, alternative treatment with modern pharmaceutical agents as well as other alternatives are highly effective, provided the cardiologist you are dealing with knows how to use medication, takes it seriously and carries it out diligently. Sad to say, most do not and prescribe an inadequate number of drugs or too low a dosage. It should also be pointed out that not only do angioplasty and bypass surgery NOT slow down the progression of the disease and its consequences, but actually accelerates it’s progression, by causing injury to endothelial membrane.
Finally, many cardiologists and surgeons will casually dismiss an alternative or alternatives to bypass surgery/ angioplasty with modern drugs and other management techniques because these alternatives are unable to eliminate or unclog the obstructed coronary artery. That is true. It is not possible to restore the obstructed coronary artery back to normal by any form of treatment. But we don't have to and nor do bypass/ Angioplasty achieve that, though somehow, it is made out to be that. What modern drug treatment does is to restore blood flow to the heart muscle in that part of the heart where blood flow is reduced. This is accomplished by dilating other blood vessels in the same area that are not blocked. At the same time other drugs reduce the workload of the heart so that the heart muscle requires less blood. This is like finding another source of income and reducing expenses if you lose your job. Once income to the heart muscle (blood flow) is adequate for the expenses (work load) of the heart, chest pains will disappear. There are other drugs, which stabilize the vulnerable plaques, minimizing the chances of their rupture, and accordingly the chances of a heart attack or death. This gives sufficient time to heart to grow new channels, using body's natural adaptive responses leading to formation of new blood vessels through angiogenesis (angio = blood vessels, genesis = birth of). The result is the formation of a vast network of small vessels that develop around the obstructed artery allowing blood to flow around the obstructed artery without resistance. In other words, the heart has put in its own bypasses with the help of medical therapy with modern drugs that is an alternative to bypass surgery. Unfortunately, such collateral vessels, as they are called, are not visible on an angiogram because they are too small to be seen by this primitive imaging technique. However, other imaging studies such as an echocardiogram or nuclear imaging will clearly show the heart muscle is functioning and contracting in a perfectly normal manner, even though the artery going to that area of the heart is partially or completely obstructed. How can that be? Obviously, blood is getting through to that heart muscle, even though this can't be seen on the angiogram---an imaging procedure that has been around since 1958 and has obvious limitations and has far outlived it’s utility. Finally, modern drug therapy is more than just an alternative to bypass surgery and angioplasty. We now recognize that certain drugs such as beta blockers, Ace inhibitors and Statins actually slow down and even stop the progression of coronary artery disease, and may even reverse some of the changes that have occurred. Neither bypass surgery nor angioplasty are capable of doing this.
In summary, an alternative or alternatives to bypass surgery or angioplasty with modern drugs and other management techniques has changed the natural history of coronary artery disease. Like so many other diseases of the past that were lethal and are now considered benign because we have effective treatment, it is time to downgrade coronary artery disease from the lethal disease it once was, to a relatively benign disorder which, like arthritis, might bother you once in a while, but should not shorten your life or significantly change it’s quality.
A study published in 1999 in the New England Journal of Medicine continues to produce controversy and infighting amongst cardiologists. The Atorvastatin VErsus Revascularization Treatment (AVERT) trial compared aggressive cholesterol -lowering (with the statin atorvastatin) to angioplasty in patients with mild to moderate coronary artery disease. The AVERT study reported that patients randomized to statin therapy had a lower incidence of later problems (including the need for later angioplasty procedures, coronary-artery bypass operations, and hospitalizations for worsening angina) than did the patients who had received angioplasties. These results stunned the cardiology community. Now slowly, a consensus seems to be emerging: a coronary artery blockage is not like Mt. Everest, needing to be dilated, bypassed or cleared, “because it’s there.” So if anyone is confronted with an advice to go for Bypass Surgery or Angioplasty, he should not think twice, but should think thrice at least. Here is a compendium of 37 research studies, which I have compiled from the published literature; conducted between late 80’s and 2001 in: New England Journal of Medicine, Journal of American College of Cardiology, Journal of American Medical Association, Archives of Internal Medicine, European Heart journal, The Lancet, Circulation and British Medical Journal. All these studies compared the quality of life and survival benefits (morbidity and mortality data) between Angioplasty and/ or Bypass Surgery on one hand and “Medical Management” on the other hand. In all of them, “Medical Management” was a clear winner, with the results being “Statistically significant”. (Full-text/ abstract available on request):
1. Non-Q-wave Myocardial Infarction Following Thrombolytic Therapy: A Comparison of Outcomes in Patients Randomized to Invasive or Conservative Post-Infarct Assessment Strategies in the Veterans Affairs Non-Q-Wave Infarction Strategies In-Hospital (VANQWISH) Trial.. Wexler,LF, Blaustein, AS, Philip W. Lavori, PW, et al. Journal of the American College of Cardiology. ; 2001; 37: 19-25.
2. Percutaneous Transluminal Angioplasty Versus Medical Treatment For Non-Acute Coronary Heart Disease: Meta-Analysis of Randomized Controlled Trials. Bucher, HC, Hengstler, P, Schindler, C, Gordon, H, Guyatt, GH. British Medical Journal. 2000; 321: 73-77.
3. Intensive Medical Therapy Versus Coronary Angioplasty for Suppression of Myocardial Ischemia in Survivors of an Acute Myocardial Infarction. Dakik HA, Kleiman NS, Farmer, JA et al. Circulation, 1998; 98: 2017-2023.
4. Outcome In Patients with Acute Non-Q Wave Myocardial Infarction Randomly Assigned to An Invasive As Compared with a Conservative Management Strategy. Boden WE, O'Rourke RA, Crawford MH, et al. New Engl J. Medicine. 1998; 338: 1785-1792.
5. Twenty-two Year Follow-up in the VA Cooperative Study of Coronary artery bypass surgery for Stable Angina. Peduzzi, P, Kamina A, Detrie, K, American Journal of Cardiology. 1998; 81; 1393-1399.
6. A Prospective Randomized Trial of Triage Angiography in Acute Coronary Syndromes Ineligible for Trombolytic Therapy. Results of the Medicine Versus Angiography in Thrombolytic Exclusion (MATE) Trial. McCullough PA, O'Neill WW, Graham M, et al. Journal of the American College of Cardiology. 1998; 32: 596-605.
7. Danish Multicenter Randomized Study of Invasive Versus Conservative Treatment In Patients With Inducible Ischemia After Thrombolysis In Acute Myocardial Infarction. DANAMI) Madsen JK, Grande P, Saunamaki K, et al. Circulation. 1997; 96: 748-755.
8. Coronary Angioplasty Versus Medical Therapy For Angina: The Second Randomized Intervention Treatment of Angina (RITA-2) Trial. RITA-2 Trial Participants. Lancet. 1997; 350: 461-468.
9. One Year Results of the Thrombolysis in Myocardial Infarction (TIMI) IIIB Clinical Trial. A randomized Comparison of Tissue-Type Plasminogen Activator Versus Placebo and Early Invasive Versus Early Conservative Strategies in Unstable Angina and Non-Q Wave Myocardial Infarction. Anderson HV, Cannon CP, Stone PH, et al. Journal of The American College of Cardiology. 1995; 26: 1643-1650.
10. The Medicine, Angioplasty or Surgery Study (MASS): A Prospective Randomized Trial of Medical Therapy, Balloon Angioplasty or Bypass Surgery for Single Proximal Left Anterior Descending Artery Stenosis. Hueb WA, Bellotti G, Oliveira SA et al. Journal of the American College of Cardiology. 1995; 26: 1600-1605.
11. Two and Three Year Results of the Thrombolysis in Myocardial Infarction (TIMI) Phase II Clinical Trial. Terrin ML, Williams DO, Kleiman, NS et al. Journal of the American College of Cardiology. 1993;22; 1763-1772.
12. Randomized Trial of Late Angioplasty Versus Conservative Management For Patients with Residual Stenosis After Thrombolytic Treatment of Myocardial Infarction. Ellis, SG, Mooney, MR. George, BS, et al. Circulation. 1992: 86; 1400-1406.
13. A Comparison of Angioplasty With Medical Therapy in the Treatment of Single Vessel Coronary Artery Disease. Parisi AF, Folland ED, Hartigan P. New Engl J Med. 1992; 326: 10-16.
14. SWIFT Trial of Delayed Elective Intervention v. Conservative Treatment After Thrombolysis With Anistreplase in Acute Myocardial Infarction. Should We Intervene Following Thrombolysis? SWIFT Study Group Trial Study Group. British Medical Journal. 1991: 302: 555-560.
15. Comparison of Immediate Invasive, Delayed Invasive and Conservative Strategies After Tissue-Type Plasminogen Activator. Rogers, WJ, Baim, DS, Gore, JM et al. Circulation. 1990: 81; 1457-1476.
16. Randomized Controlled Trial of Late In-Hospital Angiography and Angioplasty Versus Conservative Management After Treatment With Recombinant Tissue-Type Plasminogen Activator in Acute Myocardial Infarction. Barbash GI, Roth A, Hanoch H., et al. American Journal of Cardiology. 1990; 66: 538-545.
17. Comparison of Invasive and Conservative Strategies After Treatment With Intravenous Tissue Plasminogen Activator in Acute Myocardial Infarction. The TIMI study Group. N. Engl J Med 1989; 320: 618-627.
18. Thrombolysis With Tissue Plasminogen Activator in Acute Myocardial Infarction: No Additional Benefit From Immediate Percutaneous Coronary Angioplasty. Simoons, ML, Betriu, A, Collateral, J et al. The Lancet. January 30, 1988; 197-203.
19. Comparison of Medical and Surgical Treatment forh Unstable Angina Pectoris. Luchi, RJ, Scott SM, Deupree RH, et al. N. Engl. J. Medicine 1987; 316: 977-984.
20. Racial Differences in the Use of Invasive Cardiac Procedures and 1 Year Clinical Outcomes for Non-Q-Wave Myocardial Infarction Patients Randomized to Invasive vs. Conservative Management. Samar H, Heggunje PS, Deedwania PC et al. Journal of the American College Cardiology, Supplement, 2001; 37: 15A
21. A Comparison of the Impact of Practice Patterns on Outcome of Patients With Acute Coronary Syndromes in the USA and Canada: Post Hoc Analysis of ESSENCE and TIMI IIB. Batchelor, WB, Radley D, Cohen M, et al. Journal of the American College Cardiology, Supplement, 2001; 37: 359A
22. Outcome Study of Two Large Populations With Different Rates of Cardiac Interventions. Mahrer, PR. Cardiovascular Reviews and Reports, December 2000 638-651
23. Piegas, IS, Flather, M, Pogue J. et al. for the OASIS Registry Investigators. The Organization to Access Strategies for Ischemic Syndromes (OASIS) registry in patients with Unstable Angina. Am J. of Cardiology. 1999; 84(suppl): 7M-12M.
24. Comparison of Medical Care and Survival of Hospitalized Patients with Acute Myocardial Infarction in Poland and the United States. Rosamond W, Broda G, Kawalec E, et al. American J. Cardiology 1999; 83: 1180-1185.
25. Use of Coronary Angiography and Revascularization Procedures Following Acute Myocardial Infarction: A European perspective. Woods, KL, Ketley D, Agusti, A, et al European Heart Journal. 1998; 19; 1348-1354.
26. Use of Cardiac Procedures and Outcomes in Elderly Patients with Myocardial Infarction in the United States and Canada Tu JV, Pashos CL, Naylor Color Doppler, et al. N Engl J Med 1997; 336: 1500-1505.
27. Variation in the Use of Cardiac Procedures After Acute Myocardial Infarction. Guadagnoli E, Hauptman BJ, Ayanian JZ, et al. N Engl J Med 1995; 333: 573-578.
28. A Comparison of Management Patterns After Acute Myocardial Infarction in Canada and in the United States Rouleau JL, Moye LA, Pfeffer, MA et al. N Engl J Med 1993;328: 779-784.
29. Differences in the Treatment of Myocardial Infarction in the United States and Canada. A Comparison of Two University Hospitals. Pilote L, Racine N, Hlatky MA. Arch Intern Medication 1994; 154: 1090-1096.
30. Comparison of Medical Care and One and 12 Month Mortality of Hospitalized patients with Acute Myocardial Infarction in Minneapolis-St. Paul, Minnesota, United States of America and Goteborg, Sweden. McGovern OG, Herlitz J, Pankow JS, et al. Am. J Cardiol. 1997; 80: 557-562
31. Longitudinal Assessment of Neurocognitive Function After Coronary Artery Bypass Surgery. Newman MF, Kirchner JL, Phillips-Bute B, et al. N Engl J Medication 2001; 344: 395-402.
32. Coronary Stenting or Percutaneous Transluminal Coronary Angioplasty Prior to Noncardiac Surgery Increases Adverse Events: The Evidence is Mounting, Van Norman GA, and Posner, K. Journal of the American College of Cardiology. 2000; 36: 2351
33. Catastrophic Outcomes of Noncardiac Surgery Soon After Coronary Stenting. Kaluza GL, Joseph J, Lee JR, et al. Journal of the American College of Cardiology. 2000; 35: 1288-1294.
34. Results of a Second-Opinion Trial Among Patients Recommended For Coronary Angiography. Graboys TB, Biegelsen B, Lampert S, Blatt CM, Lown B. JAMA; 1992: 268 2537-2540.
35. Two to Eight Year Survival Rates in Patients Who Refused Coronary Artery Bypass Grafting. Hueb W, Bellotti G. Ramired J, et al. American Journal Cardiology. 1989;63: 155-159.
36. Prognosis of Medically Treated Patients with Coronary Artery Disease With Profound ST-Segment Depression During Exercise Testing. Podrif, PD, Graboys, TB, Lown, B. N Engl J Med. 1981; 305:1111-1116.
37. Exercise Performance-Based Outcomes of Medically Treated Patients with Coronary Artery Disease and Profound ST Segment Depression. Thompson, CA, Jabbour S, Goldberg, RJ, et al. Journal of the American College of Cardiology. 2000; 36: 2140-2145. From Harvard Medical School, the Lown Cardiovascular Research Foundation, and the University of Massachusetts Medical School

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