How treatments are creating new types of patients with heart disease.
Cardiology is one of the disciplines that has benefited most from the huge progress made in technology that has allowed a significant improvement in diagnostic and treatment capabilities; however, these aspects are only able to eliminate or mitigate a symptom, such as angina in a subject with coronary disease, dyspnoea in a subject with heart valve disease, or cyanosis in a subject with congenital heart disease, and while they can lead to improvements in quality of life and longer survival, they do not lead to a cure.
This situation has led to the formation of a new population of individuals with heart disease whose clinical histories are not yet well-defined and who require complex care, which always involves programmed clinical and instrumental follow-up. In addition to reducing acute cerebrovascular events, the advent of drugs that control high blood pressure, diabetes and heart failure has also led to a considerable decrease in mortality, which, by prolonging survival into old age, has consequently increased the population of patients which chronic heart failure.
This has resulted on a significantly higher re-hospitalisation rate, especially when these patients are not followed in dedicated cardiology facilities.
(CHF=Congestive Heart Failure)
The advent of electrical and haemodynamic monitoring and the increase in early revascularisation using fibrinolytics (substances that dissolve thrombi in the case of blockage of a coronary artery in acute myocardial infarction) and/or primary angioplasty (dilation of a coronary artery using a balloon and simultaneous implantation of a metal device known as a stent) have significantly reduced mortality from acute myocardial events in both men and women; and, especially in patients over 65 years of age, they have increased the number of cases of heart failure, a cause of late mortality.
Diagram: out of 7733 patients with myocardial infarction (MI), 5871 will develop heart failure, which will be the cause of death for 2316 of them; just 1091 subjects will not experience severe complications after myocardial infarction.
Figure: Trends for intrahospital mortality (black columns) and heart failure (red columns) between 1994 and 1999. The continuous lines indicate the total cases of mortality and heart failure that develop within 5 years in patients with myocardial infarction.
Geriatric cardiology is becoming increasingly important, not merely as regards the care demands for heart failure, but also those for myocardial revascularisation, as a consequence of the greater use of coronary angioplasty and, ultimately, of percutaneous stent placement. This situation calls for a thorough clinical investigation (cost-benefit assessment) and a more purely ethical consideration of the indications for extreme treatments.
However, it is in the congenital heart disease field that treatments have had the most remarkable impact on the epidemiological scenario.
The prevalence of all congenital heart diseases at birth is estimated to be approximately 8 per thousand live births: before the advent and consolidation of heart surgery, less than 20% of children born with heart disease reached adulthood and in most cases these patients had simple heart diseases and only rarely complex heart diseases that spontaneously reached an equilibrium between structural changes, ventricular function and pulmonary circulation and often their natural history ended due to haematological consequences rather than cardiac consequences. If we analyse the data compiled by theOffice of Population Consensus and Surveys for England and Wales indicating the deaths of patients with congenital heart disease in the various age groups, we see that in 1958 deaths were more frequent during childhood, whereas from 1986 they become more frequent over the age of 20. This trend reversal that has become increasingly evident over time is the consequence of the considerable successes of the surgical correction of congenital heart defects and the surgeon’s ability to intervene very early in the first few months or even weeks of life. It is currently estimated that in North America and Europe there are more than one and a half million adult patients with congenital heart disease, most of whom have had at least one surgical correction procedure. These patients constitute what Jane Somerville, an eminent British cardiologist, calls the new medical community of GUCH (Grown Up Congenital Heart) patients, who, despite the radical correction of their malformation, continue to require medical, and sometimes even surgical, care.
The increase in the period of time following the correction procedure is accompanied by an increase in the number of patients presenting clinical problems that affect morbidity and survival. This causes an increase in care demands that in the absence of specific preparation it is difficult to satisfy. These patients have difficulties living the “normality” that heart surgery has given them, because their aspirations clash with a scenario that is not equipped to correctly interpret their needs, which are not only clinical, but also medicolegal (physical fitness certification for sports or work), psychological-interpersonal (anxiety, depression, cognitive changes, family, pregnancy, parenthood), social, particularly with regard to employment, and social security-related.
A new identity for old nightmares.
The development of molecular medicine and in particular the ever-greater possibility of using the genetic investigations that in the past twenty years have revealed diseases that in the past were often only discovered in the presence of severe or even fatal events. These are heart diseases that often do not present clear clinical signs, and whose structural changes reside in microscopic portions of complex structures; they often involve proteins that are abnormal because they were produced by genes that have undergone mutations, infinitesimal changes able to produce severe structural consequences in the heart cells (myocytes). These patients have inherited or familial genetically-determined cardiomyopathies, characterised by a high arrhythmic risk that can compromise their survival. They are patients who need to be identified and included in regular follow-up programmes; there have been considerable improvements in diagnostic abilities, especially in the non-invasive procedures that make it possible to quantify the risk of adverse events (risk stratification) and to adopt the preventative measures best suited to the level of risk, from pharmacological therapy to the implantation of life-saving devices such as defibrillators. Both prevention and therapy must be individualised in order to make it possible to safely achieve a quality of life that is not limited by excessive medicalisation.
The scenario has changed, because there has been a change in the protagonists: heart disease, heart disease patients, the cardiologists; this calls for a change in the type of care provided, and considering the complexity of the clinical situations and the various factors that contribute to causing it, interdisciplinary intervention, able to draw on skill sets that also include not purely medical skills but also address the external environment, is essential.