ECG monitoring of treatment response in pulmonary arterial hypertension patients.
BACKGROUND
The potential use of the ECG for monitoring treatment effects in patients with pulmonary arterial hypertension (PAH) has not been investigated. We evaluated whether the ECG is useful for monitoring treatment response based on changes in pulmonary vascular resistance (PVR).


METHODS
An ECG was recorded in 81 PAH patients at the time of diagnostic right heart catheterization and after 1 year of treatment. Patients were treated according to the guidelines. Patients were divided into two groups based on PVR (ie, < 500 or > 500 dyne x s x cm(-5)). A positive treatment response was defined as a > 25% decrease in PVR to an absolute PVR of < 500 dyne x s x cm(-5).


RESULTS
At baseline, the 19 patients with a PVR of < 500 dyne x s x cm(-5) had a significantly lower P amplitude in lead II, a less rightward oriented QRS axis, and a more rightward T axis than the 62 patients with a PVR of > 500 dyne x s x cm(-5). Overall (n = 81), the mean (+/- SD) change in PVR was -143 +/- 360 dyne x s x cm(-5) after 1 year of treatment (p < 0.001). Twelve patients (19%) with a baseline PVR of > 500 dyne x s x cm(-5) were classified as responders. Receiver operating characteristic analysis determined that the P amplitude in lead II (area under the curve [AUC], 0.80; 95% confidence interval [CI], 0.67 to 0.94; p < 0.01), QRS axis (AUC, 0.70; 95% CI, 0.52 to 0.89; p = 0.03), and T axis (AUC, 0.90; 95% CI, 0.82 to 0.97; p < 0.001) were important determinants of treatment response. The presence of a P amplitude in lead II of < 0.175 mV and a T axis of >or= 25 degrees combined had a positive and negative predictive value for treatment response of 0.81 (95% CI, 0.37 to 0.96) and 0.94 (95% CI, 0.86 to 0.99), respectively.


CONCLUSIONS
Routine ECG evaluation can be an important contribution in the assessment of treatment response in PAH patients.
Henkens
Ivo R
IR
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
Gan
C Tji-Joong
CT
Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
van Wolferen
Serge A
SA
Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
Hew
Miki
M
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
Boonstra
Anco
A
Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
Twisk
Jos W R
JWR
Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands.
Kamp
Otto
O
Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
van der Wall
Ernst E
EE
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
Schalij
Martin J
MJ
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
Vonk Noordegraaf
Anton
A
Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands. Electronic address: a.vonk@vumc.nl.
Vliegen
Hubert W
HW
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D006328:Cardiac Catheterization; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology
D000959:Antihypertensive Agents