Clinical variables improve efficacy of ECG scores to diagnose the left ventricular hypertrophy in general population
Authors: Jamiolkowski J , Chlabicz M , Paniczko M , Sowa P , Szpakowicz M , Lapinska M , Jurczuk N , Drobek N.A , Sawicka E , Raczkowski A , Kaminski K.A 
Published: November 2020

Abstract

Left ventricular hypertrophy (LVH) is an important risk factor of various cardiovascular (CV) diseases and sudden death. Electrocardiography (ECG) is commonly used to detect LVH, but it has poor sensitivity, especially in high cardiovascular risk patients. Although echocardiography (ECHO) is a better, it is less available, and more expensive. Aim: To improve ECG scores to diagnose LVH in a general population.

Methods
The study was conducted in 2017–2019 in a representative sample of area residents. 717 volunteers randomly chosen from the local population were examined. Due to incomplete data, QRS complex duration ≥120ms, fascicular blocks, bundle branch blocks, paced rhythm, 216 people were excluded. Physical examination, ECG, ECHO and laboratory assessment were performed. In ECG LVH defined as &gt;28mm for men, &gt;20mm for women using Cornell index; &gt;17mm for both sexes using Lewis index. In ECHO LV mass was calculated using the Devereux Formula and indexed by body surface area (left ventricular mass index – LVMI). The LVH was defined as LVMI ≥115 g/m2 for man and ≥95 g/m2 for women. Cardiovascular risk was calculated based on the ESC SCORE and additional risk categories published in the latest ESC guidelines. We analyzed 4 models to predict the probability of LVH at ECHO: Model 1: Cornell index; Model 2: Lewis index; Model 3: Cornel index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c); Model 4: Lewis index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c). Associations between LVH and clinical and biochemical variables were earlier analyzed using multiple linear regression models, these parameters were independently associated with LVH.

Results
A total of 501 patients were included. The average age of patients was 49.0±15.35 years, and 203 probants (40.5%) were male. We developed a novel score to assess the probability of LVH at ECHO in general population based on nine items (age, sex, body mass index, office BPs, Cornell index or Lewis index, QRS time, hs-TnT, and HbA1c). Additional clinical parameters improved sensitivity of Cornell index up to 86.0% (AUC:0.8011; 95% CI:0.748–0.854) from 64.9% (AUC:0.6450; 95% CI:0.573–0.716) in general population, to 92.9% (AUC:0.8423; 95% CI:0.760–0.924) from 64.3% (AUC:0.6481; 95% CI:0.518–0.779) in low CV risk patients, to 69.2% (AUC:0.6767; 95% CI:0.544–0.809) from 38.5% (AUC:0.5284; 95% CI:0.352–0.705) in moderate CV risk, and to 73.3% (AUC:0.7151; 95% CI: 0.609–0.821) of Lewis index from 50.0% (AUC: 0.5630; 95% CI:0.448–0.678) in high and very-high CV risk class.

Conclusions
Addition of clinical parameters to ECG indices in the diagnosis of LVH markedly improves their diagnostic efficacy both in general population and in higher risk groups. The new score may be useful in guiding the appropriateness of ECHO study in general population, and especially in moderate and high CV risk patients, who are not always aware of the increased CV risk.
ROC curves for recognize LVH.

Funding Acknowledgement
Type of funding source: Public Institution(s). Main funding source(s): Medical University of Bialystok for Bialystok PLUS study