The frail elderly are by definition weak and delicate and its consideration of frailty and the impact on decision making is growing in importance in cardiology due to the aging population. Take the treatment of non ST elevation myocardial infarction (NSTEMI). It is highly researched with clearly defined evidence based treatment protocols. Diagnosis is made with clinical history, ECG and troponin. There follows the prescription of potent anti-platelet/anti-thrombotic and then often angiography and for some percutaneous coronary intervention (PCI), Whilst we might debate the benefits of PCI in patients with stable angina, beyond reduction in symptoms, this is not in question in heart attack patients. Just in case you’re wondering about the evidence the Cochrane Review of the 4 major trials comparing a conservative to PCI strategy in NSTEMI showed no effect on overall mortality but reduced rates of refractory angina and re-hospitalization in the shorter term and myocardial infarction (MI) in the longer term. The PCI strategy was associated with a doubling in the risk of procedure-related MI and increased risk of bleeding. What all this is really saying is that if you stent a coronary narrowing now you are less likely to have to do it later.
But there is a catch with these clinical trials. How many included patients who were 86 years old, walking with a frame, weak because of low muscle mass and on more than a dozen medications for all sorts of other medical problems, How many of these patients were frail elderly people. Of course very few since this type of patient isn’t able to comply with rigors of a clinical trial and are not attractive to the research team. Most trial patients are younger, with less co-morbidity, able to attend for follow up visits and able to consent they are good trial patients. Our problem is that the frailer patients occupy an increasing part of our workload. These patients have cardiac problems but this is in addition to problems are about being able to walk to the toilet, being able to bathe, the loss of independence, fear of what the future may hold, worry about their elderly spouse or whose going to look after the cat. There has been a trend in over the last 5 years for such elderly patients to be managed more by specialists rather than generalists or geriatricians. This makes it reasonable to ask whether we (cardiologists as a group) are well equipped to care for such patients with complex medical needs beyond having a blinkered view and focusing only on the heart. We may also fall into the trap of regarding these patients with therapeutic nihilism and therefore to deny the application of invasive therapies on the basis that the patient is too frail to withstand the procedure. Yet by definition such patients have the highest risk of death of all we treat and therefore may potentially have the greatest benefit. Weighing up the risks and benefits is difficult since measurement of both is uncertain.
In the absence of clinical trials we look to registries and observational studies to try and fill in the evidence gaps. But caution is required since these are non-randomized studies and the risk of bias, even after the usual multivariate regression of all potential confounders has been applied, is strong. A paper just published in Heart illustrates this. The authors looked NSTEMI management and frailty. The study from Italy followed 698 patients with a mean age of 83 years. A quarter had ST elevation and the rest non-ST elevation MI and each patient was scored using the Silver Code (SC) frailty score. There are over 25 different scores of frailty all of them have their pros and cons. The SC is heavily weighted by age and a diagnosis of cancer and a SC score of ≥11 is used to define a person as frail. In the study 50% of patients were treated with PCI the rest with medical therapy. There are no surprises that if you had a STEMI and were admitted to a hospital that could do 24/7 PCI on site you were more likely to get a PCI. We all know that if the patient is delivered direct to the catheter laboratory the threshold for performing angiography and hence PCI is very low compared to a patient who is paid free and seen 48h after admission in a peripheral hospital without PCI facilities on site. The PCI patients were younger, male, had less heart failure, less anaemia and we less likely to have renal failure. In other words they had less co-morbidity. For every 1 point the SC score increased the chance of the patient having PCI decreased by 11%.
The authors followed the outcome of the patients over the next year and used mortality as their end point. This is good because it is straightforward, simple to measure and meaningful. They found that PCI did not reduce the risk of death in people with a low SC score (0–3) but the benefit increased as the score increased such that people with a SC score of ≥11 had a 74% reduction in risk if they had a PCI. The conclusion from this study was that cardiologists are not offering treatment to the frail elderly who are in fact the very patients who benefit most from the procedure. Of course there is another explanation and that is the frail patients with an SC score of ≥11 were a heterogeneous group with some more frail than other. Those who got PCI were different even after adjustment for factors such as renal function, heart failure and age. As Justice Potter said “I know it when I see it.” The decision to refer the patient for PCI is made not just on administrative factors such as age, creatinine and number of medications but on a holistic assessment of the patient balancing the risk and benefit of the procedure with outcome for the patient. What we really need is a randomised study with mortality as its end point to address the question of PCI in very elderly presenting with MI until then clinical acumen will have to do.