**Core Concept**
The thoracoscore is a clinical prediction rule used to estimate the risk of mortality in patients with pulmonary embolism (PE). It takes into account various clinical and laboratory parameters to provide a quantitative estimate of the risk. The thoracoscore is based on a complex scoring system that uses multiple variables to predict the probability of in-hospital mortality.

**Why the Correct Answer is Right**
The thoracoscore includes several components, such as age, heart rate, systolic blood pressure, cardiac arrest, tachycardia, hypotension, renal failure, elevated troponin, and increased respiratory rate. These variables are used to calculate a numerical score that correlates with the risk of mortality. The correct answer is not a component of the thoracoscore.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is indeed a component of the thoracoscore, as it is associated with an increased risk of mortality in patients with PE.

**Option B:** This option is also a component of the thoracoscore, as it is a marker of cardiac dysfunction and is associated with a higher risk of mortality.

**Option C:** This option is not a component of the thoracoscore, as it is not directly related to the clinical or laboratory parameters used in the scoring system.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the thoracoscore is a useful tool for estimating the risk of mortality in patients with PE, but it should not be used in isolation to make clinical decisions. The thoracoscore should be interpreted in conjunction with other clinical and laboratory parameters to provide a comprehensive assessment of patient risk.

**Correct Answer: C. This option is not a component of the thoracoscore.**