Computerized two-lead resting ECG analysis for the detection of coronary artery stenosis after coronary revascularization

Noninvasive mathematical analysis of spectral electrocardiographic components for coronary lesions of intermediate to obstructive stenosis severity-relationship with classic and functional SYNTAX score

OBJECTIVES

The aim of this study was to evaluate the relationship between the multifunction cardiogram (MCG), and SYNTAX score (SS) and functional SYNTAX score (FSS) in detecting the presence of intermediate to obstructive coronary lesions.

BACKGROUND

Performing coronary angiography (CAG) and measuring fractional flow reserve (FFR) to calculate the SS and FSS is inherently invasive and adds complexity.

METHODS

The MCG was obtained and analyzed before performing CAG in 87 consecutive subjects with suspected coronary artery disease who were scheduled for elective CAG. The patients were divided into three groups according to risk based on high, borderline, and low MCG scores. The SS was determined, as well as FSS but only by counting lesions prone to functional ischemia (FFR ≤ 0.8). The relationship between the MCG and the SS and FSS was evaluated.

RESULTS

The MCG was the only test significantly associated with the SS (odds ratio, 2.92 [1.60 - 5.31], P < 0.001) and FSS (odds ratio, 3.66 [1.95 - 6.87], P < 0.001). A high MCG score had a specificity of 92.6% (89.0-96.2%) and 92.3% (89.0-95.6%), and a predictive accuracy of 72.4% (67.6-77.2%) and 82.8% (78.7-86.8%) for the prediction of SS and FSS, respectively.

CONCLUSIONS

The MCG showed high specificity and predictive accuracy especially for the FSS, suggesting that it is useful not only in identifying functionally significant ischemia but also in reducing unnecessary CAGs.

Noninvasive Detection of Functional Myocardial Ischemia: Multifunction Cardiogram Evaluation in Diagnosis of Functional Coronary Ischemia Study (MED-FIT)

BACKGROUND

Multifunction cardiogram (MCG) is a computer-enhanced, resting electrocardiogram analysis developed to detect hemodynamically relevant coronary artery disease (CAD). Based on data from previous studies suggesting excellent diagnostic accuracy in detecting CAD, MCG (approved by the Food and Drugs Administration) received a Current Procedure Terminology (CPT) code in 2010 in United States. However, there is no previous study validating MCG by using fractional flow reserve (FFR) as the reference standard.

METHODS

Multifunction cardiogram Evaluation in Diagnosis of Functional coronary Ischemia sTudy (MED-FIT) was designed as a single-center, prospective study enrolling 100 stable patients with suspected CAD scheduled for coronary angiography. The primary and secondary analyses evaluated the diagnostic performance of the MCG severity score to detect functional myocardial ischemia by FFR ≤0.80, and angiographically significant coronary stenosis (percent diameter stenosis ≥50%) by quantitative coronary angiography.

RESULTS

The current analysis set consisted of 91 patients in whom MCG data with adequate quality was obtained. The prevalence of positive functional myocardial ischemia and angiographically significant stenosis in the current study was 42.7% and 41.8%, respectively. Area under the receiver operating characteristics curve (AUC) of the MCG severity score for functional myocardial ischemia and angiographically significant stenosis was low (AUC 0.51, 95% confidence interval [CI] 0.38-0.63, and AUC 0.58, 95%CI 0.46-0.70, respectively). Sensitivity, and specificity of the MCG severity score for functional myocardial ischemia and angiographically significant stenosis was also low (32%/67%, and 37%/72%) using a cutoff value of 4.0.

CONCLUSIONS

Diagnostic performance of the MCG severity score was poor for both functional myocardial ischemia, and angiographically significant stenosis.

Non-invasive assessment of functionally significant coronary stenoses through mathematical analysis of spectral ECG components

Objectives

The aim of this study was to evaluate the accuracy of the Multifunction CardioGram (MCG) in detecting the presence of functionally significant coronary ischaemia.

Methods and results

This prospective study evaluated the accuracy of the MCG, a new ECG analysis device used to diagnose ischaemic coronary artery disease (CAD). A consecutive 112 participants suspected to have CAD who were scheduled for elective coronary angiography (CAG) from October 2012 to December 2013 were examined. Their predictive values of relevant ischaemia were measured by MCG, standard ECG and Framingham Risk Score (FRS) and compared. Five levels of ischaemia based on CAG findings adjusted by fractional flow reserve (FFR) values and three levels of MCG score of high, borderline or low were used. The MCG (OR=2.67 (1.60 to 4.44), p<0.001) was the only test significantly associated with ischaemia level. The FFR values for individual MCG scores with low, borderline and high were 0.77 (0.70 to 0.86), 0.78 (0.71 to 0.82) and 0.69 (0.65 to 0.77), respectively, p=0.042. A high MCG score had a specificity of 90.4% (87.0% to 93.9%) in model 1 adjusted by FFR≤0.8 threshold and of 87.0% (83.2% to 90.8%) in model 2 adjusted by FFR≤0.75 threshold, and a negative predictive value of 82.5% (78.3% to 86.7%) in model 1 and of 83.8% (79.6% to 87.9%) in model 2 for the prediction of severe ischaemia.

Conclusions

The MCG showed high specificity with a high negative predictive value, suggesting that the MCG could be used not only to identify functionally significant ischaemia but to reduce unnecessary CAGs.

Trial registration number

UMIN ID: 000009992.

A paired-comparision of the Multifunction Cardiogram (MCG) and sestamibi SPECT myocardial perfusion imaging (MPI) to quantitative coronary angiography for the detection of relevant coronary artery obstruction (≥70%) - a single-center study of 116 consecutive patients referred for coronary angiography

BACKGROUND

An analysis of the US National Cardiovascular Data Registry has revealed that only 38% of patients referred for coronary angiography after non-invasive coronary testing have relevant coronary obstruction (CO) (≥70%) of one or more coronary arteries.

METHODS

A single-center trial was undertaken in 165 consecutive, symptomatic patients with either known or suspected coronary disease and/or valve disease(VHD) who agreed to undergo cardiac catheterization and coronary angiography if stress myocardial perfusion imaging was abnormal. A total of 116 patients with abnormal SPECT MPI tests, persistent chest pain, or significant VHD underwent final analysis. An MCG coronary obstruction (CO) score of ≥ 4.0 was considered indicative of relevant CO (≥70%) in one or more coronary arteries. Angiographic results were finalized by consensus of two angiographers.

RESULTS

CO (≥70%) was present in 53 of 116 patients (46%). The MCG CO score was significantly higher for patients with relevant CO (5.4 ± 1.9 vs. 2.5 ± 1.9). The MCG correctly classified 103 of the 116 patients (89%) enrolled in the study as either having or not having CO (≥70%) (sensitivity- 91%; specificity- 87%; NPV- 92%; PPV- 86%). SPECT MPI was abnormal in 99 of the 116 (85%) patients undergoing catheterization, but correctly classified only 54 of the 116 patients (47%) entered in the study as either having or not having relevant CO (sensitivity-85%; specificity-14%; NPV - 53%; PPV- 45%).

CONCLUSIONS

The MCG was shown in this paired-comparison trial with SPECT MPI to safely and accurately identify patients with relevant CO (≥70%) prior to catheterization.

Serum ferritin and transferrin levels as serologic markers of methylene diphenyl diisocyanate-induced occupational asthma

BACKGROUND

Although methylene diphenyl diisocyanate (MDI) may induce occupational asthma in the workplace, the pathogenic mechanisms are unclear.

OBJECTIVES

By using bronchoalveolar lavage fluid, we sought to identify proteins that were differentially expressed between subjects with MDI-induced occupational asthma (MDI-OA) and asymptomatic exposed controls (AECs).

METHODS

To find proteins that were differentially expressed between the MDI-OA and AEC groups, 2-dimensional electrophoresis was performed by using bronchoalveolar lavage fluid obtained from subjects after MDI-specific inhalation challenge. The selected protein spots were then identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The clinical relevance of the differentially expressed spots was compared by ELISA using sera from the MDI-OA/eosinophilic bronchitis, AEC, and unexposed healthy control groups. Receiver operating characteristic curves were then plotted, and the sensitivity and specificity were determined.

RESULTS

Twenty-three protein spots were identified that distinguished the subjects with MDI-OA from those in the AEC group. Among them, ferritin expression was downregulated whereas transferrin expression was upregulated in subjects with MDI-OA compared with AEC; these results were validated by ELISA using sera from the MDI-OA/EB and AEC groups. To identify subjects with MDI-OA, the optimal serum cutoff levels were 69.84 ng/mL for ferritin and 2.48 microg/mL for transferrin. When these 2 parameters were combined, the sensitivity was 71.43% and the specificity was 85.71%.

CONCLUSION

Serum ferritin and transferrin levels are associated with the phenotype of MDI-OA.