Irish Medical News


Advances in treatment of chronic total occlusion


Marie Feely learns of the unique advances in the Mater Private Hospital’s Heart Centre that are improving patients’ lives


At a special lecture organised by the Mater Private Hospital on managing patients with chronic total occlusions (CTO) recently, IMN spoke to Dr Brendan Doyle, a leading consultant cardiologist at the Hospital, to discover the advantages of the complex procedure. Dr Doyle previously trained in the procedure with US expert Dr William L Lombardi, Adjunct Assistant Clinical Professor of Cardiology at Stanford University, US, at his hospital in Seattle, who also spoke at the meeting held in Dublin.

Dr Doyle spoke to IMN at the Heart Centre after the first of these procedures was carried out at the hospital. According to Dr Doyle, the main advantage of this new procedure is that patients who may otherwise need stents or would need to undergo bypass surgery can opt for this alternative. “This kind of procedure can offer patients the chance to get blood flow restored to the heart muscle without the need for bypass surgery, so it’s a less invasive way of doing things,” he told IMN. Dr Lombardi described the process that can remove blockages within blood vessels in the heart.

“There may be a blockage, which can be anywhere from a millimeter long to more than 100mm long, and there’s no vessel that you can see or know the course that it passes. So the challenge is to get a guide wire from one end to the other end and be in the right place, without leaving the artery or causing damage in between,” he said. Dr Lombardi said this sets out a “big challenge” and described techniques that have been developed to combat this. “One is where we make a dissection along the vessel and get past the distal cap. Then there’s a special balloon that lays in next to the lumen distally and it facilitates us to put a wire back into theblood vessel. Then we put the stent in,” he said. Another technique has been developed to allow the surgeon “go through tiny little blood vessels with a guide wire”.

He advised IMN there is “a special catheter we can bring in behind it and actually go at the blockage from both sides. That’s another technique that helps us keep the vessel successfully opened”. Dr Lombardi worked alongside Dr Doyle, who he described as one of the leading CTO experts in Ireland today, in order to add “extra refinement to these techniques” which will increase the number of patients who can benefit from this novel procedure. Dr Doyle noted that the technique eliminates much of the trauma associated with bypass surgery for CTO. “For most of these CTO procedures which we are carrying out, patients go home the following morning and they don’t need a general anaesthetic,” Dr Doyle explained. “They’re awake and able to talk to us during the procedure.”

Usually, procedures take approximately two hours, but can take up to four hours. Dr Doyle said that one Saturday each month at the Heart Centre will be set aside solely for these procedures in the Mater Private. “We decided to set aside dedicated time so we can spend as long as we need to get the job done; there is no other interference, no other people calling on you, no distractions,” he said. Dr Doyle also described the patients who are candidates for the procedure. “Patients who have symptoms of angina or breathlessness but previously may have been told that the blockages were too bad and couldn’t be fixed, may be suitable.”

“For those types of patients, there’s now an opportunity to actually fix the blockages, whereas previously they would have been told that they needed a bypass, or perhaps they needed a bypass but weren’t fit for it.” He explained that there is likely no unsuitable candidate, although the risks and benefits of the procedure for each patient need to be carefully considered. “Anybody who has a chronic occlusion in their coronary artery is suitable for one of these techniques. There’s no particular limitation from a technical standpoint,” he continued. “The main advantage is for patients who might otherwise need a bypass or for those patients for whom bypass might be a particularly risky operation, such as a more elderly patient or patient who’s had previous stroke.”

He explained that the procedure is also an effective way of treating coronary disease in patients who might have just a single vessel occluded. “They may have angina or dyspnoea but generally we don’t send patients for a bypass if they only have one blockage.” In the past, these patients would have been treated with medication alone. “They would often still have symptoms, so may have poor quality of life. In the past, there may not have been enough there to persuade you to recommend a bypass, so in this situation now CTO-PCI can be an alternative to taking lots of anti-anginal medication that may be only partially effective. This can improve the quality of life of those patients and lessen the need for multiple medications,” Dr Doyle said.

In his lecture, Dr Lombardi explained that CTO are commonly encountered complex lesions identified in about 15 per cent of all patients referred for coronary angiography. In Dr Lombardi’s centre in the US, from January 2005 to April 2006 2,169 diagnostic angiograms were carried out and almost 40 per cent of these demonstrated at least one CTO. Chronic total occlusion remains the most powerful predictor of referral for coronary bypass surgery, Dr Lombardi explained. “The benefits of CTO percutaneous coronary intervention (PCI) include symptom relief, improved left ventricular function, and potentially a survival advantage associated with success when compared with failed CTO-PCI.” In addition, successful PCI of CTO is associated with improved quality of life and reduced ischaemia, Dr Lombardi added, echoing Dr Doyle.

Remaining barriers to attempting CTO-PCI in the US include operator inexperience, the perception of increased risk of CTO-PCI, and financial disincentives to operators and hospitals. Dr Lombardi explained that to overcome operator inexperience, participation in CTO clubs, the invitation of guest operators, and a dedicated CTO day can be implemented at institutions committed to learning advanced CTO-PCI techniques so that operators can overcome the barriers and offer patients access to percutaneous therapy when it is clinically indicated – which is what has happened at the Mater Private. Dr Lombardi gave more advice on setting up a CTO-PCI service, quoting the “three P’s”: Practice, persistence and patience. Doctors should identify patients appropriate for the procedure, he explained.

Patients with symptoms or attributable left ventricular impairment in whom the risk-benefit estimate justifies the procedure should be considered for revascularisation. In patients with an otherwise long life expectancy, completed revascularisation for multivessel disease, left anterior descending coronary artery CTO, and non-left anterior descending coronary artery CTO with large ischaemic burden should be considered. Technique innovations have improved the safety and effectiveness of CTO PCI, said Dr Lombardi. “On the basis of the collective emerging data, it seems that success rates of 80 per cent to 90 per cent with the contemporary strategies and techniques are consistently achievable in experienced hands with a safety profile comparable to standard risk-adjusted PCI.”

He said utilising a “hybrid strategy” for the procedure (antegrade wire escalation, antegrade dissection reentry, and retrograde wire escalation and dissection re-entry techniques) optimises opportunity for success as well as potentially shortening procedure times. “There is a great opportunity to benefit public health by expanding CTO revascularisaition; we under-treat these patients,” he said.

References on request

Published in association with the Mater Private Hospital


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