We are discussing the topic of diseases of the heart arteries, which is also known as coronary artery disease or ischaemic heart disease with Consultant Cardiologist, Dr. Upul Wickramarachchi of Lanka Hospitals, Colombo.
Dr. Wickramarachchi received his MBBS from the University of Peradeniya and obtained MRCP (UK), MD Research (UEA, UK), and CCT in Cardiology (UK) and is in the specialist registries of the General Medical Council UK and here in Sri Lanka. He has worked in the National Health Service in the UK for 15 years, and lastlyas a Consultant Interventional Cardiologist at the Norfolk and Norwich University Hospital, UK before moving back to Sri Lanka at the end of last year. His interventional training was at the Norfolk and Norwich University Hospital and Royal Papworth Hospital, Cambridge.
Q: What is coronary artery disease/IHD?
A: Coronary arteries are the blood vessels that supply blood/oxygen to heart muscle cells. From the second decade of our lives, cholesterol plaques start developing in these vessels.
Initially, they are called fatty streaks which later organize into more advanced forms of cholesterol plaques. When these depositions progress, causing the lumen of a heart artery to narrow, the supply of blood to heart muscles can get affected. For example, if there is a narrowing of more than 70% it is generally accepted that this would hamper the blood flow causing the patient to have chest pain (stable angina) on exercise.
In a more proximal area such as the left main stem heart artery, a 50% or more narrowing can cause symptoms. If left untreated these narrowing’s can get worse further and cause symptoms on minimal exertion or at rest (unstable angina).
In some patients, these cholesterol plaques can rupture without any pre-warning causing a blood clot to form around it and this is when a patient develops a heart attack (myocardial infarction). This can occur in a plaque that is not causing a significant luminal narrowing too.
Q: What are the risk factors to develop coronary artery disease?
A:Coronary artery disease is considered a multifactorial disease entity. The risk factors include male gender, advancing age, diabetes mellitus, high blood pressure, high cholesterol, obesity (high body mass index/BMI) or central obesity (high waist-to-hip ratio), family history of premature coronary artery disease, and environmental pollution.
Q: What are the symptoms or ways of presentation of ischemic heart disease?
A: When a person experiences central chest pain/tightness/heaviness/ache on exertion it is called stable angina. The location of the pain can vary from person-to-personi.e., for some on the left of the chest, some around the throat/upper chest, arms only, or the upper part of the tummy or in-between the shoulder blades. Some present with breathlessness on exertion.
A sudden bout of chest pain of similar character as described above, associated with nausea, vomiting, and sweating radiating to arms/jaw/teeth/back indicates a heart attack. In such a situation medical attention should be sought immediately.
Q: How do you diagnose heart artery disease/ischaemic heart disease/ coronary artery disease?
A: This depends on the presentation and there are a few ways to get to the bottom of the problem. If a patient presents with symptoms on exertion (stable angina) in addition to the cardiovascular examination, basic investigations such as ECG and echocardiogram will be arranged by your Cardiologist.
Also, an exercise ECG/treadmill test is a very useful, non-invasive, relatively low-cost test to assess for exercise-induced lack of blood supply to the heart muscle (if there are no contraindications for the test).
This gives an idea about one’s exercise capacity too. But both patients and prescribers should be aware of its limitations too, mainly its relatively low sensitivity (ability to pick an abnormality) and specificity (when abnormal what percentage of that is truly due to heart artery disease) which is in the order of 70-80% and this varies with age and gender too.
Other noninvasive test modalities such as CT coronary angiogram (CTCA) are also available with high sensitivity and specificity, but one has to bear in mind that this is an anatomical test only and it does not assess the impact on heart muscle (degree of lack of blood supply to the heart muscle) caused by an artery narrowing if found. Also, it is very important to consider the pretest probability of having heart artery disease in a patient before having any of these tests as these are more useful for individuals with low to moderate pretest probability. CTCA can be used in high pretest probability patients too but ideally when it can be coupled with additional assessments such as CT FFR to detect the impact on the heart muscle of a narrowing if found (degree of lack of blood supply to heart muscles). Other tests such as stress echocardiograms stress nuclear scan/MIBI and cardiac stress MRI scans are also very useful in assessing for the presence of significant coronary artery narrowings and their impact on the blood supply to the heart muscle.
For patients with high pretest probability, if persistent symptoms are there despite initial tablet management, an invasive coronary angiogram should be considered, which still is the gold standard test to detect heart artery narrowings.
For a patient presenting with a heart attack, the approach is different. Usually, a heart attack is diagnosed based on symptoms, a rise in the heart enzyme called troponin, abnormalities on the ECG, and or echocardiogram. The commonest cause of a heart attack is a rupture of a cholesterol plaque inside a heart artery and the formation of a clot.
If the clot is large enough to block the whole artery (which gives rise to specific ECG changes) the recommended test/treatment is immediate (under two hours) coronary angiography and unblocking the artery. Other types of heart attacks too do warrant a coronary angiogram to look for any blocks/narrowings of heart artery/ies unless there is a good reason not to do so.
Q: What are the treatment options available for heart artery disease/coronary artery disease/ischaemic heart disease?
A: Three mainstays of treatment are tablet (medical) management, coronary angioplasty (balloon/stent treatment), or coronary artery bypass graft surgery (CABG).
For patients with chest pains only on exertion (stable angina), the first line of treatment is tablets. There are several classes of tablets that we recommend for these patients which include a blood thinning tablet such as Aspirin and cholesterol-lowering statin and medications to lower the heart rate and expand heart arteries.
If tablet treatment is not controlling symptoms adequately or if the area of the heart muscle areainvolved is large, then coronary angiography plus or minus balloon/stent treatment (if severe narrowing/s found) or bypass surgery should be considered if indicated.
If presenting with a heart attack generally it is recommended to go ahead with a coronary angiogram to assess for any heart artery narrowings. If there are severe one or two narrowings a balloon/stent treatment is recommended and if all three heart arteries or two arteries with complex narrowings a bypass surgery will be recommended generally.
Q: Are there any novel treatment methods?
A: As everyone knows, implantation of coronary stent/s is a well-established method of treating heart artery narrowings. The stents have come a long way from their inception in the 1980s and are good compared to the early days. Stents were invented to be used as a bail-out option when balloon-only angioplasty fails or is not successful. Down the line, this became the mainstay of treatment and is now being used ubiquitously.
However, stents are permanent implants once inserted and do carry a small percentage risk of complications that accumulates every year since implantation. Scientific evidence indicates that when used in excessive lengths, small arteries, and bifurcation lesions (narrowing of the main heart artery involving an origin of a branch artery) requiring overlapping stents, the adverse outcome rates are higher than usual.
Also, after stent implantation, two types of anti-platelet (blood thinning) medications are used minimally for one year (generally) and sometimes for longer periods. If such a patient develops a bleeding disorder, it can be very tricky to manage both aspects. Not having a permanent implant allows the heart artery to return /heal back to its normalcy as much as possible and avoids stent related complications.
Due to these reasons, scientists have been exploring ways of treating heart artery narrowings without putting in a permanent implant for many years now. Even the newest versions of drug-eluting stents try to have the least amount of a footprint with less or no polymer now, compared to the previous generation.
One of the ‘no permanent implant’ techniques was called bioresorbable scaffolds (BVS/BRS), a stent like semi-permanent structure that dissolves within 2-3 years, but this did not take off due to early signs of increased clot formation within the scaffold.
A technology that enables the advantages of ‘implant-free’ technology from day 1 but also avoids complications of the previously mentioned scaffold system is called drug-coated balloon (DCB) angioplasty. This involves treating a heart artery narrowing with a balloon and if successful in expanding the narrowing, then carrying out the final treatment with the drug-coated balloon. It carries a chemotherapeutic drug that gets absorbed into the vessel wall to counteract the possible re-narrowing process that can occur after treating a heart artery (similar drugs are used in current Drug-eluting stents). If the final appearance of the artery after treatment is satisfactory (during the angiogram), the Cardiologist leave the heart artery without implantation of a stent.1 This allows the vessel to heal and potentially to regain its natural ability to contract/expand/bend with heart muscle contractions. The table below summarises the potential benefits of an ‘implant-free’ coronary angioplasty technology.
There is scientific evidence to prove that this treatment is non-inferior to drug-eluting stents when treating coronary arteries of less than 3 mm size and also it’s used in special circumstances such as high bleeding risk patients, re-narrowed stents and bifurcation lesions (where there is a branch artery at the place of a narrowing). There is data to support its use in large-size (more than 3mm) coronary arteries too.6 Some studies show that there is a trend towards less heart attacks and reduced mortality with drug-coated balloon angioplasty treatment but more studies are needed to confirm these findings. Also, there is scientific evidence to support that endothelial function (activities of the innermost cell layer of the heart artery wall) is better after DCB treatment compared to stents.
Also studies have shown that the lumen of DCB-treated segments can get bigger once healed (late lumen gain) a phenomenon that is not seen with stents. Percentage cholesterol plaque volume has also been shown to be less after drug-coated balloon angioplasty.8 Not caging the vessel with a permanent stent allows the artery to receive a coronary artery bypass graft if needed down the line which is another advantage.
In a patient with stable angina (non-heart attack patients), the second blood thinning medication will be needed only for one month following DCB treatment. Even for a heart attack patient, if the need arises such as developing a bleeding episode, the second blood thinning medication can be stopped after a month relatively safely.
Both Cardiologists and patients receiving/consenting to this treatment should be aware that it is still not included in the European/American guidelines but there is an international consensus document published with regards to its use.9 Acute complications after any heart procedure is dreaded by both the treating doctor and the patients and there could be understandable anxiety especially when the treated area is not covered by a stent.
All the studies published show that acute complication rates after DCB treatment is similar to those after drug eluting stent treatment and present only in a very small percentage of patients.
It is of paramount importance that the treating doctor is trained in using this technology with adequate exposure and experience (as it is a different form of angioplasty to implanting stents) like for any other medical procedure. I was fortunate enough to be trained by Dr. Simon Eccleshall, a UK expert in DCB angioplasty as his first research fellow and later on as a Consultant in the UK. We have together published many articles, authored book chapters, and also presented at numerous international conferences regarding our work including a late-breaking trial at the EuroPCR (Europe’s largest interventional cardiology conference) in Paris, in May 2021.
Q: Is there any particular relevance to Sri Lanka in using this technology?
A: Yes, very much so. I feel this technology will be very useful in Sri Lanka as the vast majority of our patients have small (less than 3mm) heart arteries (coronary arteries) and there is ample evidence now to support its use in them. Also, diffuse diseases (narrowings involving long lengths) are common due to our increased risks, and DCB angioplasty will help avoidthe implantation of long lengths of stents (what are called full metal jackets) which are known to cause a higher incidence of long-term complications. Also, DCBs will avoid requiring overlapping stents for bifurcation lesions.
Last not least, even though I have no scientific data to support it, one of my observations is that our patient cohort is much younger than the European/developed world counterparts. In these young/very young patients, not having a permanent implant may give rise to lesser complications in the long term, and even in the worst-case scenario of needing repeat treatment (if) down the line, the procedures will be relatively less complicated as it will be similar to treating a native vessel (artery in the original form) and also will have the ability to receive a bypass graft.
It is certainly gaining popularity in other Asian countries such as Japan, South Korea, Singapore, and Malaysia as well as in European nations after being invented in Germany.Is drug-coated balloon (DCB) technology available in Sri Lanka?
Yes, I am very happy to inform you that we have thetechnology available in Sri Lanka now for the benefit of our patients. I feel that it is a very useful tool to have in the armamentarium of an interventional Cardiologist and also patients should be aware that such a technology is there if someone is interested.
References:
• Wickramarachchi U, Eccleshall S. Drug-coated Balloon-only Angioplasty for Native Coronary Disease Instead of Stents. Interv Cardiol. 2016 Oct;11(2):110-115. doi: 10.15420/icr.2016:17:3. PMID: 29588716; PMCID: PMC5808490.
• Elgendy IY, Gad MM, Elgendy AY, Mahmoud A, Mahmoud AN, Cuesta J, Rivero F, Alfonso F. Clinical and Angiographic Outcomes With Drug-Coated Balloons for De Novo Coronary Lesions: A Meta-Analysis of Randomized Clinical Trials. J Am Heart Assoc. 2020 May 18;9(10):e016224. doi: 10.1161/JAHA.120.016224. Epub 2020 May 15. PMID: 32410493; PMCID: PMC7660863
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• Venetsanos D, Lawesson SS, Panayi G, Tödt T, Berglund U, Swahn E, Alfredsson J. Long-term efficacy of drug coated balloons compared with new generation drug-eluting stents for the treatment of de novo coronary artery lesions. Catheter Cardiovasc Interv. 2018 Nov 1;92(5):E317-E326. doi: 10.1002/ccd.27548. Epub 2018 Feb 26. PMID: 29481718.
• Vos NS, Fagel ND, Amoroso G, Herrman JR, Patterson MS, Piers LH, van der Schaaf RJ, Slagboom T, Vink MA. Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stent in Acute Myocardial Infarction: The REVELATION Randomized Trial. JACC Cardiovasc Interv. 2019 Sep 9;12(17):1691-1699. doi: 10.1016/j.jcin.2019.04.016. Epub 2019 May 21. PMID: 31126887.
• Merinopoulos I, Gunawardena T, Corballis N, Bhalraam U, Gilbert T, Maart C, Richardson P, Ryding A, Sarev T, Sawh C, Sulfi S, Wickramarachchi U, Wistow T, Mohamed MO, Mamas MA, Vassiliou VS, Eccleshall SC. Paclitaxel drug-coated balloon-only angioplasty for de novo coronary artery disease in elective clinical practice. Clin Res Cardiol. 2022 Sep 14. doi: 10.1007/s00392-022-02106-y. Epub ahead of print. PMID: 36104455.
• Kawai T, Watanabe T, Yamada T, Morita T, Furukawa Y, Tamaki S, Kawasaki M, Kikuchi A, Seo M, Nakamura J, Tachibana K, Kida H, Sotomi Y, Sakata Y, Fukunami M. Coronary vasomotion after treatment with drug-coated balloons or drug-eluting stents: a prospective, open-label, single-centre randomised trial. EuroIntervention. 2022 Jun 3;18(2):e140-e148. doi: 10.4244/EIJ-D-21-00636. PMID: 34757917.
• Ann SH, Balbir Singh G, Lim KH, Koo BK, Shin ES. Anatomical and Physiological Changes after Paclitaxel-Coated Balloon for Atherosclerotic De Novo Coronary Lesions: Serial IVUS-VH and FFR Study. PLoS One. 2016 Jan 29;11(1):e0147057. doi: 10.1371/journal.pone.0147057. PMID: 26824602; PMCID: PMC4733051.
• Jeger RV, Eccleshall S, Wan Ahmad WA, Ge J, Poerner TC, Shin ES, Alfonso F, Latib A, Ong PJ, Rissanen TT, Saucedo J, Scheller B, Kleber FX; International DCB Consensus Group. Drug-Coated Balloons for Coronary Artery Disease: Third Report of the International DCB Consensus Group. JACC Cardiovasc Interv. 2020 Jun 22;13(12):1391-1402. doi: 10.1016/j.jcin.2020.02.043. Epub 2020 May 27. PMID: 32473887.