Cardiothoracic ratio within the "normal" range independently predicts mortality in patients undergoing coronary angiography

Abstract

Objective: To determine whether cardiothoracic ratio (CTR), within the range conventionally considered normal, predicted prognosis in patients undergoing coronary angiography. Design: Cohort study with a median of 7-years follow-up. Setting: Consecutive patients undergoing coronary angiography at Barts and The London National Health Service (NHS) Trust. Subjects: 1005 patients with CTRs measured by chest radiography, and who subsequently underwent coronary angiography. Of these patients, 7.3% had a CTR >0.5 and were excluded from the analyses. Outcomes: All-cause mortality and coronary event (non-fatal myocardial infarction or coronary death). Adjustments were made for age, left ventricular dysfunction, ACE inhibitor treatment, body mass index, number of diseased coronary vessels and past coronary artery bypass graft. Results: The risk of death was increased among patients with a CTR in the upper part of the normal range. In total, 94 (18.9%) of those with a CTR below the median of 0.42 died compared with 120 (27.8%) of those with a CTR between 0.42 and 0.49 (log rank test p,0.001). After adjusting for potential confounders, this increased risk remained (adjusted HR 1.45, 95% CI 1.03 to 2.05). CTR, at values below 0.5, was linearly related to the risk of coronary event (test for trend p = 0.024). Conclusion : In patients undergoing coronary angiography, CTR between 0.42 and 0.49 was associated with higher mortality than in patients with smaller hearts. There was evidence of a continuous increase in risk with higher CTR. These findings, along with those in healthy populations, question the conventional textbook cutoff point of >0.5 being an abnormal CTR.

The cardiothoracic ratio and all-cause and cardiovascular disease mortality in patients undergoing maintenance hemodialysis: results of the MBD-5D study

“…In addition, the CTR was found to correlate independently with LVH and target organ damage in hypertensive patients [ 9 ]. The CTR is likely to be a predictor all-cause and cardiovascular disease (CVD) mortality in patients with mild-to-moderate heart failure [ 9 – 11 ] or those undergoing coronary angiography [ 12 ]. However, it remains unclear that a higher CTR is associated with increased mortality among a hemodialysis-treated population [ 13 – 16 ].…”

Establishing the cardiothoracic ratio using chest radiographs in an indigenous Ghanaian population: a simple tool for cardiomegaly screening

“…6 When the normal value for the local population is known, it serves as a baseline for proper assessment.…”

“…4 Chest radiography is the most commonly used modality for the detection of cardiomegaly and the cardiothoracic ratio has been used as an important indicator of cardiac size. 5 It is a simple and cheap tool used in the estimation of heart size 6 and a value of 50% is generally considered to indicate the upper limit of normal. However, this value is not always correct and many cardiac and extracardiac factors influence this measure, such as the examination technique, the patient's biotype, the patient's physiological status, thoracic alterations (scoliosis, pectus excavatum), and the size of the lungs, the breathing phase, the cardiac cycle phase, and heart rate at the time of examination.…”

Prevalence and Positive Predictive Value of Poor R-Wave Progression and Impact of the Cardiothoracic Ratio

“… 2) 8) Subjects with PRWP tend to be female, younger, weigh less, and shorter in height than those without PRWP. Considering that a low cardiothoracic ratio is frequent in the young and those who weigh less, 9) it is also postulated that PRWP is associated with a low cardiothoracic ratio.…”