O2-pulse - heart rate inclination angle difference (IAD) in assessing cardiovascular function in patients with adult congenital heart disease

Abstract

INTRODUCTION: Cardiopulmonary stress test (CPT) plays important role in management of adult congenital heart disease (ACHD). Our aim in the current study is to investigate the role of a novel CPT parameter, O2-pulse-Heart rate inclination angle difference (IAD), that integrates chronotropic and inotropic responses to exercise, in the assessment of ACHD. METHODS: ACHD patients and healthy controls were enrolled prospectively for this observational study. Participants underwent transthoracic echocardiography and CPT on a bicycle ergometer with a ramp protocol, respectively. IAD was calculated in addition to standard CPT parameters in each patient. RESULTS: Twenty-one patients with ACHD (mean age: 28 ± 12 years, 14 male, 66 %) and 79 healthy controls (mean age: 34 ± 6, male 100 %) were included in the study. Patients had significantly lower systemic ventricle ejection fraction (60±8% versus 69±4%, p< 001) and higher systolic pulmonary artery pressure (33±13 versus 21±5 mmHg, p<0.01). Execise duration (7.4±4 versus 10.1±2.3 minutes, p=.007), maximal oxygen consumption (VO2max) (1524±614 versus 2398±391, p<001) and IAD (- 5.9±13.7 versus 1.2±13.1°) were lower while VE/VCO2 was higher (31±5.1 versus 28.8±3.3,p=.030) in ACHD patients. In univariate analysis, age (r=0.236,p=.18), diagnosis of ACHD (r=- 0.205,p=.41), NT-proBNP (r=-0.870,p=.002), VO2max (r=0.334,p=.001) and VE/VCO2 (r=-0.273, p=.006) were associated with IAD. IAD was independently associated with VE/VCO2 when adjusted by age, diagnosis of ACHD, LVEF and VO2max (β=-1.2, CI -1.892--0.508, R2=0.242). DISCUSSION and CONCLUSION: In this study, we demonstrated that the novel CPT parameter IAD might have a potential role in assessing cardiovascular function in patients with ACHD. This role should be further investigated in larger cohorts. / Öz: GİRİŞ ve AMAÇ: Kardiyopulmoner stres testi (KPT) erişkin doğumsal kalp hastalarının (EDKH)'nin yönetiminde önemli rol oynar. Bu çalışmada amacımız, egzersize kronotropik ve inotropik yanıtları intergre eden yeni bir parametre olan O2-vuru - Kalp hızı eğim açı farkının (EAF) EDKH'nın değerlendirilmesindeki rolünün değerlendirilmesidir. YÖNTEM ve GEREÇLER: EDKH ve sağlıklı kontroller prospektif olarak bu çalışmaya dahil edilmiştir. Katılımcılara sırasıyla transtorasik ekokardiyografi ve bisiklet ergometri üzerinde rampa protokolünde KPT uygulanmıştır. Her hastada standart KPT parametrelerine ek olarak EAF hesaplanmıştır. BULGULAR: EDKH olan 21 hasta (ortalama yaş 28 ± 12, 14 %66 erkek) ve 79 sağlıklı kontrol (ortalama yaş 34 ± 6, %100 erkek) bu çalışmaya dahil edilmiştir. Hastalar, sağlıklı kontrollere göre önemli derecede düşük sistemik ventrikül ejeksiyon fraksiyonuna (60±8% ve 69±4%, p< .001) ve daha yüksek pulmoner arter basınçlarına (33±13 versus 21±5 mmHg, p<001) sahipti. EDKH'de egzersiz süresi (7.4±4 ve 10.1±2.3 dakika, p=.007), maksimal oksijen tüketimi (VO2max) (1524±614 ve 2398±391, p