Cardiothoracic Ratio: Important Prognostic Tool in Heart Failure Patients Who Are Candidates for Heart Transplantation M. Berman, D. Aravot, T. Ben-Gal, G. Sahar, A. Sagie, and B. Vidne W ITH THE INCREASING mean age of the popula- tion and longer survival of patients with chronic heart disease, the incidence of congestive heart failure (CHF) has risen constantly in recent years. Nowadays, expensive tests are carried out to assess the extent of heart failure and to determine the best medical or surgical treatment necessary to maintain the delicate balance of the disease. No doubt, the most severe patients are those in whom medical treatment and assist devices have failed, and their only chance of survival is heart transplantation (HTx). The prognosis of congestive heart failure patients who are candidates for heart transplantation depends on several factor, such as exercise test, echocardiography, ejection fraction, cardiac catheterization, renal and hepatic function, etc. In this study, we show that a simple measurement of the cardiothoracic ratio (CTR), based on chest X-ray radiogra- phy, is quite helpful in assessing the magnitude of the disease and may serve as a reliable prognostic predictor with regard to the patient’s place on the waiting list. PATIENTS AND METHODS The study included 32 patients (29 men and 3 women), aged 41 to 70 years (mean  SD: 57.4  7.22), all suffering from end-stage heart failure and on the institution’s waiting list for cardiac transplantation. For each patient, the same roentgenographic team measured the CTR, based on a posteroanterior chest X-ray. The CTR was defined by Danzer 1 in 1919 and is calculated by tracing a vertical line through the heart and measuring the greatest distance to the left and to the right cardiac border, with the sum of the two being the transverse cardiac diameter. The transverse thoracic diameter is the greatest width of the chest, measured from the inner surface of the ribs. Dividing the cardiac diameter by the thoracic diameter gives the cardiothoracic ratio. The existence of pericardial effusion was estimated by echocardiography. Functional status was estimated by New York Heart Association (NYHA) score, dividing the third status into IIIa and IIIb, while IIIa is “patients with cardiac disease resulting in marked limitation of physical activity, comfortable at rest and less than ordinary physical activity resulting in fatigue, palpitations and dyspnea” and IIIb is the same as IIIa with the complaint of anginotic pain, creating a total of five categories. During a period of 1 year, the patients just mentioned were followed, with two endpoints: (1) heart transplantation, and (2) death while on the waiting list. The values were analyzed using a bivariate (scatter)plot calcu- lating the coefficient of linear correlation (Pearson’s correlation), with P  .05 considered statistically significant. RESULTS Mean follow-up was 10.5  2.3 months, ranging from 3 to 13 months (CTR: minimum 0.48, maximum 0.75, mean  SD 0.59  0.06; NYHA: minimum 1, maximum 5, 3.6  0.26). A strong and significant correlation was found be- tween the increase in CTR and the rise of NYHA func- tional status score, with r = .68 and P = .015 (Fig 1). During follow-up, four patients died due to congestive heart failure and seven patients underwent heart transplan- tation (Table 1). Table 1 clearly shows that patients with CTR  0.58 suffered from higher mortality and morbidity than those with CTR  0.58. Only one patient demon- strated mild pericardial effusion on echocardiography, so CTR accurately represented the cardiac size. DISCUSSION Chest X-ray is often performed to evaluate patients with heart failure. What is the significance of increased CTR in From the Heart—Lung Transplant Unit, Department of Cardio- thoracic Surgery, Rabin Medical Center (Beilinson Campus) of the Sackler Faculty of Medicine, Tel-Aviv University, Petach- Tikva, Israel. Address reprint requests to Dr Dan Aravot, Heart–Lung Trans- plant Unit, Department of Cardiothoracic Surgery, Rabin Medical Center (Beilinson Campus), 49100 Petach-Tikva, Israel. Table 1. Patient Outcome, Based on Cardiothoracic Ratio (CTR) CTR  0.58 CTR  0.58 Heart transplantation: 1 patient, 3.1% (status 2 before HTx) Heart transplantation: 5 patients, 15.6% (status 1 before Htx); 1 patient, 3.1% (status 2 before HTx) Died due to congestive heart failure while on waiting list: 1 patient (3.1%) Died due to congestive heart failure while on waiting list: 3 patients (9.3%) © 2000 by Elsevier Science Inc. 0041-1345/00/$–see front matter 655 Avenue of the Americas, New York, NY 10010 PII S0041-1345(00)00958-1 Transplantation Proceedings, 32, 727–728 (2000) 727