Relation between N-terminal pro-brain natriuretic peptide levels and response to enhanced external counterpulsation in chronic angina pectoris.
OBJECTIVE
Although enhanced external counterpulsation (EECP) provides symptom reduction in many patients with severe angina pectoris, one-quarter of patients fail to respond. Earlier reports have not clearly established whether and how EECP responders may be identified pre-hoc. We hypothesized that clinical and biochemical data may be used to predict EECP response.


METHODS
We explored a database of n=53 patients who had undergone clinically indicated EECP during 35 1-h sessions in our unit (65±7 years; 49 male), and sought to clarify which factors are predictive of response. Efficiency of counterpulsation was measured as the diastolic augmentation (DA) ratio, and was recorded both at beginning and end of the EECP treatment course. An increase in 6-min walk (6MW) distance of 5% was indicative of clinical response.


RESULTS
Response occurred in 28 patients (53%; nonresponse in n=25, 47%). Responders had shorter baseline 6MW distance (377±81 vs. 445±62 m; P<0.01), lower left ventricular ejection fraction (48±9 vs. 54±8%; P<0.05), frequently had an increase in DA ratio during the EECP treatment course (23/28 vs. 5/28 with unchanged or decreased DA ratio; P<0.05), and higher levels of N-terminal pro-brain natriuretic peptide [NT-proBNP; 256 (123-547) vs. 62 (26-444) ng/l, P<0.01]. In multivariate logistic regression, response was independently predicted by baseline 6MW distance and baseline NT-proBNP levels (P<0.05 for both; model sensitivity: 82%, specificity: 72%, accuracy: 79%).


CONCLUSIONS
There is larger clinical benefit of EECP in patients with greater functional impairment and higher levels of NT-proBNP.
Department of Cardiology M52, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
Anders
A
Sahlén
Eline
E
Wu
Andreas
A
Rück
Inger
I
Hagerman
Gunilla
G
Förstedt
Christer
C
Sylvén
Margareta
M
Berglund
Tomas
T
Jernberg
D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D002908:Chronic Disease; D015908:Counterpulsation / Q000379:methods*; D003971:Diastole; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D020127:Recovery of Function; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016138:Walking
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain