A clinical study compared two types of replacement valves for patients with severe mitral valve regurgitation (a leaking mitral valve):
The data from the study is shown in the table below:
| Measurement | Mechanical Mitral Valve (MMV) | Bioprosthetic Mitral Valve (BMV) |
|---|---|---|
| Number of patients in the study | 450045004500 | 320032003200 |
| Number of patients experiencing thromboembolism (blood clots) within 1 year | 180180180 | 323232 |
| Percentage of patients alive after 5 years | 82%82\%82% | 79%79\%79% |
| Percentage of patients requiring repeat valve surgery within 5 years | 2.0%2.0\%2.0% | 14.0%14.0\%14.0% |
Explain why a damaged, leaking mitral valve leads to a reduced ability to perform aerobic exercise.
Give one conclusion comparing the rate of thromboembolism within 1 year between the two groups. Include calculations of percentages to support your conclusion.
Based on the data provided and your biological knowledge, evaluate the choice of a Bioprosthetic Mitral Valve (BMV) compared to a Mechanical Mitral Valve (MMV).
44 exam-style questions on AQA GCSE Biology 2.2 Animal tissues, organs and organ systems, covering 2.2.1 The human digestive system, 2.2.2 The heart and blood vessels, 2.2.3 Blood, 2.2.4 Coronary heart disease: a non-communicable disease, 2.2.5 Health issues, 2.2.6 The effect of lifestyle on some non-communicable diseases, and 2.2.7 Cancer. Each one has a worked solution and a mark scheme showing where the marks go.