Angina is a chronic heart condition that has a substantial impact on our health and social services, and on the population, society and the economy. Treatment with a coronary stent (thin metal tube) is intended to relieve angina, and around 100,000 people are treated with a stent in the NHS each year. Coronary artery bypass graft (CABG) surgery is reserved for patients with extensive coronary atherosclerosis – a condition where arteries become clogged with fatty substances called plaques, or ‘atheroma’. Around 14,000 patients undergo CABG in the NHS each year.
In this study, we will focus on angina and stents. Recent research has suggested that around 2 in 5 patients report angina within one year of receiving a stent. This implies that a considerable number of patients in the UK may be affected – potentially around 40,000 people each year. The underlying reasons for this are currently under-researched and poorly understood. The explanations may include problems with the small vessels within the heart muscle that lead to a condition called ‘microvascular angina’. Stents do not help with small vessel problems, and in fact, may even make small vessel problems worse.
COVID-19 infection leads to heart and blood vessel injury. Whether COVID-19 infection impacts on angina and clinical outcomes, including in patients who have received a coronary stent, is unknown.
This research will focus on angina before and after COVID-19 infection. The research will also assess angina occurring after stents in patients who have had COVID-19 infection. Advances in linked electronic patient records now enable studies of episodes of care in hospital and at the GP. We will therefore study NHS data at a national (UK) level. We will assess the number (%) of patients who attend their GP and hospitals for angina, including after receiving a stent, and we will estimate the NHS costs attached to these visits and medication use. We wish to make these assessments before, during and after the COVID-19 pandemic by examining a period of at least 10-years before and at least 5-years after the pandemic. This should provide sufficient information to assess the impact of angina, including after stent treatment in the NHS before, during and after the COVID-19 pandemic.
We will assess the costs and health economic impact associated with these episodes of care, and their changes over time. We will then estimate whether alternative treatment approaches could be cost-effective for the NHS. A future study is anticipated to assess the effects of COVID-19 infection status on anginal symptoms in patients following CABG.