Color-Coded Tissue Doppler Imaging in ACS Patients
Color-Coded Tissue Doppler Imaging in ACS Patients
A total of 227 patients were included in the study. The median follow up time was 53 (48–58) months. During this period 85 (37%) patients reached the combined endpoint, among them 42 (19%) died, 48 (21%) had a MI and 52 (23%) were readmitted because of heart failure. Baseline characteristics, laboratory data and final diagnoses at the index event in all patients and in those with and without a subsequent event are listed in Table 1. Patients with an event were older and had more often hypertension and a previous history of heart failure. They also had a higher level of NT-proBNP and a lower eGFR. Coronary angiography was performed in 192 patients, of which 109 and 25 underwent percutaneous coronary intervention (PCI) and coronary bypass surgery (CABG), respectively.
Peak systolic velocity could be measured in all except 3 (1%) patients, whereas EF Simpson and WMS could not be assessed in 19 (8%) and 9 (4%) patients, respectively. 2D-strain could not be obtained in 41 (18%) of the patients and the corresponding number for E/e' was 28 (12%). The results of the echocardiographic measurements are listed in Table 2. When assessing the interobserver variability between two observers regarding PSV measurements the CV was 5.9%. The correlation (Spearman's rho) between global PSV calculated from 6 basal segments and PSV calculated from only the septal and lateral segment was 0.91.
Patients with an combined event had lower median PSV than those without (4,4 cm/s) vs. (5,3 cm/s), (p<0.001). These groups also differed significantly regarding EF Simpson, WMS, strain and E/e'-ratio (Table 2). In ROC analyses, the AUC (Area under curve) was larger for PSV than for the other parameters but the differences did not reach statistical significance (Table 3). When patients were divided into tertiles according to the PSV measurements the long term risk of subsequent cardiac events increased with decreasing PSV (Figure 2). The association between PSV and outcome was apparent for all individual endpoints (Table 4).
(Enlarge Image)
Figure 2.
Combined endpoint (death, myocardial infarction or readmission because of heart failure) in relation to PSV measurement.
All tested echocardiographic parameters except 2D-strain remained independently associated with outcome when these variables one at the time were adjusted for age, gender, diabetes, hypertension and previous heart failure (Table 5, model 1). When patients in the third tertile according to PSV (>5.5 cm/s) were used as reference the HR(95%CI) increased to 1.65 (0.80–3.37) p=0.169, and 3.16 (1.58–6.35) p=0.001 in the second and first tertile, respectively. In model 2 where NT-proBNP and eGFR were added to the model, only PSV, and E/e' and remained independent predictors of outcome (Table 5, model 2). When including PSV in the model, PSV was the only echocardiographic parameter independently associated with outcome (Table 5, model 3).
When we included intervention with PCI or CABG in the model, PSV remained significantly associated with outcome, (HR(95%) 0.66 (0.51–0,84), p=0.001).
Results
A total of 227 patients were included in the study. The median follow up time was 53 (48–58) months. During this period 85 (37%) patients reached the combined endpoint, among them 42 (19%) died, 48 (21%) had a MI and 52 (23%) were readmitted because of heart failure. Baseline characteristics, laboratory data and final diagnoses at the index event in all patients and in those with and without a subsequent event are listed in Table 1. Patients with an event were older and had more often hypertension and a previous history of heart failure. They also had a higher level of NT-proBNP and a lower eGFR. Coronary angiography was performed in 192 patients, of which 109 and 25 underwent percutaneous coronary intervention (PCI) and coronary bypass surgery (CABG), respectively.
Echocardiographic Acquisition and Measurements
Peak systolic velocity could be measured in all except 3 (1%) patients, whereas EF Simpson and WMS could not be assessed in 19 (8%) and 9 (4%) patients, respectively. 2D-strain could not be obtained in 41 (18%) of the patients and the corresponding number for E/e' was 28 (12%). The results of the echocardiographic measurements are listed in Table 2. When assessing the interobserver variability between two observers regarding PSV measurements the CV was 5.9%. The correlation (Spearman's rho) between global PSV calculated from 6 basal segments and PSV calculated from only the septal and lateral segment was 0.91.
Prognostic Value of Peak Systolic Velocity in Comparison to Other Echocardiographic Data
Patients with an combined event had lower median PSV than those without (4,4 cm/s) vs. (5,3 cm/s), (p<0.001). These groups also differed significantly regarding EF Simpson, WMS, strain and E/e'-ratio (Table 2). In ROC analyses, the AUC (Area under curve) was larger for PSV than for the other parameters but the differences did not reach statistical significance (Table 3). When patients were divided into tertiles according to the PSV measurements the long term risk of subsequent cardiac events increased with decreasing PSV (Figure 2). The association between PSV and outcome was apparent for all individual endpoints (Table 4).
(Enlarge Image)
Figure 2.
Combined endpoint (death, myocardial infarction or readmission because of heart failure) in relation to PSV measurement.
Independent Predictors of Outcome
All tested echocardiographic parameters except 2D-strain remained independently associated with outcome when these variables one at the time were adjusted for age, gender, diabetes, hypertension and previous heart failure (Table 5, model 1). When patients in the third tertile according to PSV (>5.5 cm/s) were used as reference the HR(95%CI) increased to 1.65 (0.80–3.37) p=0.169, and 3.16 (1.58–6.35) p=0.001 in the second and first tertile, respectively. In model 2 where NT-proBNP and eGFR were added to the model, only PSV, and E/e' and remained independent predictors of outcome (Table 5, model 2). When including PSV in the model, PSV was the only echocardiographic parameter independently associated with outcome (Table 5, model 3).
When we included intervention with PCI or CABG in the model, PSV remained significantly associated with outcome, (HR(95%) 0.66 (0.51–0,84), p=0.001).
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