By Dr Arun Gopi,
Bala, a 75-year-old man, was returning home from a walk in the park. As he reached the first floor of his building, he felt breathless and uneasy. He sat down on the stairs hoping that some rest would make the feeling go away, but there was no improvement. He managed to knock on the nearest door before collapsing. He was rushed to the hospital where after conducting appropriate tests, a heart attack was diagnosed. The cardiologist then carried out a special X-ray imaging called coronary angiography (CAG) and found that one of the major arteries supplying blood to Bala’s heart was blocked. His doctor immediately performed a procedure called percutaneous coronary intervention (PCI) and inserted a stent to keep the artery open. Bala was discharged after a short stay with strict dietary instructions and follow-up medications that would maintain blood flow and keep his heart healthy. But after a year, his symptoms returned and he was rehospitalised. What went wrong? Let us understand his condition better.
Coronary artery disease – most common reason for death in the elderly
Coronary artery disease (CAD) or ischaemic heart disease (IHD) is the umbrella term used to denote conditions caused due to lack of blood flow to the heart. This happens due to a continuous buildup of fatty material in the coronary arteries (which supply blood to the heart) forming a ‘plaque,’ which in turn reduces blood supply to the heart. Sometimes the plaque breaks and causes a sudden blockage of blood supply leading to an acute coronary syndrome (ACS). According to the Global Burden of Disease (GBD), CAD/IHD affects 1,655 per 1 lakh population worldwide and is expected to rise to 1,845 per 1 lakh population by 2030. CAD was responsible for 9 million deaths globally. In India, CAD occurs in 1,197 per 1 lakh population. CAD is the most common cause of death in the elderly with 3 out of 10 deaths occurring due to ACS. This danger is growing as the elderly population (≥60 years) worldwide is set to increase significantly in the coming years.
Depending on the type of blockage, the patient can have a reduced blood supply to a region of the heart causing angina (chest pain) or a complete block which can result in the death of heart tissue (heart attack). ACS, on the other hand, is an emergency condition that is normally diagnosed by an electrocardiogram (ECG) and blood tests. It is treated by clot-busting drugs and/or with a non-surgical method called PCI to clear the plaque. During PCI, the doctor inserts a long, thin tube called a balloon catheter via the wrist or top of the leg and guides it to the blocked area. The balloon is then inflated to widen the artery and restore blood flow. Sometimes a stent, a small tube-like structure, is placed in the formerly blocked area to prevent it from closing again. Even after this, stent might not function effectively if the stent is not placed properly or when the area gets blocked again, leading to the return of symptoms. This may require repetition of the procedure.
Diagnosis and treatment of CAD – complexities in the elderly
Though CAD is common in the elderly, its diagnosis is often delayed since the symptoms may be different (e.g. lack of chest pain or presence of breathlessness, nausea, vomiting, etc.). The symptoms may occur at a later stage and the disease could be more complex/advanced than in younger patients. The majority of the elderly population is frail, suffers from other coexisting conditions such as diabetes/hypertension/kidney disease and is on multiple medications. The coronary arteries in the elderly are commonly more twisted and present with increased calcium deposition. These challenges make use of invasive procedures such as PCI less likely in these patients due to fear of potential complications However, the availability of better techniques has caused a 3-fold increase in the number of PCIs conducted per 1 lakh patients ≥75 yrs from 2000 to 2007. Hence age alone should not be a criterion for deferring PCI in the elderly. Careful selection of the patient who is eligible for PCI can be made based on the patient’s clinical characteristics and the clinician’s judgement.
Optimising PCI and improving outcomes with cutting-edge techniques
The key aspects which have made PCI safer for the elderly include swift diagnosis, the timing of PCI (faster door-to-balloon time), appropriate access site, second or third-generation drug-eluting stents made from biocompatible polymers, bleeding avoidance strategies and better imaging techniques. CAG has long been considered the accepted method for guiding PCI. However, CAG is of limited use in complex clinical conditions which are more common in the elderly. It may not always give an accurate estimation of the blockage. This can affect clinical decisions such as the type or length of the stent to be used.
The latest advances in PCI techniques and imaging modalities now help the clinician customise the treatment strategy depending on the patient’s characteristics. Intracoronary imaging techniques such as intravascular ultrasonography (IVUS) and optical coherent tomography (OCT) and physiological measurements such as Fractional Flow Reserve (FFR), when combined with clinical data help in guiding procedures, improving assessment of the patient’s outcome and avoiding specific complications.
FFR, which compares the blood flow in a blocked vs. normal artery, helps the clinician decide on the severity of the blockage and whether PCI is essential or can be deferred. Especially in patients with multiple blockages, FFR-guided PCI helps identify blockages that need to be stented vs. those which can be managed with medication alone. Studies show that FFR-guided PCI results in lesser adverse effects such as death and heart attacks as well as lower costs vs. CAG-guided PCI. FFR is a part of European Society of Cardiology (ESC) and American Heart Association (AHA) guidelines and is considered the gold standard for PCI guidance.
On the other hand, both IVUS and OCT improve the quality of PCI. IVUS uses sound waves and OCT uses light to create accurate images of the interior of the vessel being studied and these methods provide accurate information in complex cases. OCT/IVUS can be used before PCI to assess the calcification in the artery, blood flow, size/length of the stent and after PCI to evaluate the expansion of the stent, the presence of a clot (if any) and stent positioning. Studies have shown that compared to CAG, IVUS-guided PCI prevented repeated procedures and reduced adverse heart-related events. Similarly, OCT-guided PCI decreased the risk of death and heart attacks. One study showed that when used pre- or post-PCI, OCT guidance had an impact on the procedures in >6 out of 10 patients. Both IVUS and OCT have been included in the recommendations made by international organisations such as the ESC/European Association for Cardiothoracic Surgery. An integrated system that combines FFR and OCT is also available which further refines the process.
CAD is often more complex in the elderly and it is important to ensure that procedures used for its diagnosis and treatment are as accurate as possible to avoid future complications. Newer options such as FFR, IVUS and OCT help the clinician decide on the best possible treatment. The ultimate beneficiary of these tools is the elderly and vulnerable patient who gains a better standard of care. The resultant decrease in unnecessary procedures, chances of death and adverse events can help reduce overall healthcare costs. However, in addition to all this, leading a heart-healthy life with appropriate diet restrictions and exercise will continue to remain the core of the patient’s care continuum.
(The author is HOD-Electrophysiology, Consultant Cardiologist and Electrophysiologist, MetroMed International Cardiac Centre, Kozhikode. The article is for informational purposes only. Please consult medical experts and health professionals before starting any therapy, medication and/or remedy. Views expressed are personal and do not reflect the official position or policy of the Financial Express Online.)