A clinical study compared two methods of replacing a damaged aortic heart valve in elderly patients:
The data from the study is shown in the table below:
| Measurement | SAVR | TAVI |
|---|---|---|
| Number of patients in the study | 350035003500 | 250025002500 |
| Number of patients experiencing major bleeding within 30 days | 224224224 | 808080 |
| Percentage of patients alive after 3 years | 88%88\%88% | 85%85\%85% |
| Percentage of patients requiring a permanent pacemaker within 1 year | 4.0%4.0\%4.0% | 12.0%12.0\%12.0% |
Explain why a damaged, leaking heart valve leads to a reduced ability to perform aerobic exercise.
Give one conclusion comparing the rate of major bleeding within 30 days 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 TAVI compared to SAVR.
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.