Coronary Territory Research Articles

Inferior and anterior QRS fragmentation have different prognostic value in patients who received an implantable defibrillator in primary prevention of sudden cardiac death

AimsQRS fragmentation (fQRS) has been proposed as a predictor of sudden cardiac death (SCD) and all-cause mortality in ischemic (ICM) and non-ischemic cardiomyopathy patients. However the value of fQRS in patients with a LVEF <35% is a matter of debate. MethodsAll consecutive patients with an indication for an ICD in primary prevention of SCD were included in a retrospective registry from 1996 until 2013. Twelve lead electrocardiograms before implant were analyzed for the presence of fQRS in different regions. Adjusted Cox regression analysis for first appropriate ICD shock (AS) and all-cause mortality was performed. ResultsIn total 407 patients were included with a mean follow-up of 4.2±3.3y (age 60.6±11.9y, 15.7% female and 52.8% ICM). fQRS was present in 46.7% of patients, predominantly inferior (30.7%) followed by anterior (21.4%) and lateral (11.1%) coronary artery territories. fQRS was significantly more prevalent in ICM (p=0.004).Inferior fQRS was an independent predictor of a first AS within 1y (HR 2.55, 95%CI 1.28–5.07) and 3y (HR 1.90, 95%CI 1.14–3.18) after implantation. Whereas, anterior fQRS was an independent predictor of all-cause mortality within 1y (HR 4.58, 95%CI 1.29–16.19), 3y (HR 3.92, 95%CI 1.77–8.65) and the complete follow-up (HR 2.22, 95%CI 1.33–3.69). Lateral fQRS was only a predictor of late (>3y of follow-up) all-cause mortality (HR 2.04, 95%CI 1.09–3.81). ConclusionsfQRS in a specific coronary artery territory might be promising to discriminate arrhythmic from mortality risk. Inferior fQRS was a predictor of early arrhythmia, while anterior fQRS was related to mortality.

The In Vivo Morphology of Post-Infarct Ventricular Septal Defect and the Implications for Closure

ObjectivesThe aim of this study was to define the dynamic in vivo morphology of post-infarct ventricular septal defect (PIVSD), which has not been previously described in living patients. BackgroundPIVSD is a devastating complication of acute myocardial infarction. MethodsThe anatomic features of PIVSD, as demonstrated by computed tomography or magnetic resonance imaging, were retrospectively reviewed. ResultsThirty-two PIVSDs were assessed, 16 left coronary artery and 16 right coronary artery PIVSDs. PIVSDs were large (mean maximum dimension 26.5 ± 11.5 mm, mean area 5.2 ± 4.2 cm2) and oval (mean eccentricity index 1.7 ± 0.5), with thin margins (diastolic mean thickness 5 mm from the edge of the PIVSD 6.4 ± 3.0mm), and only 22% of PIVSDs were entirely confined to the septum. The defects could be larger in diastole or systole. The stem of the largest available Amplatzer occluder stem (St. Jude Medical, St. Paul, Minnesota) filled only 50% of defects. Patients with small defects may survive without closure. Without closure, those with large defects die. If accepted for closure, PIVSD size and coronary territory did not predict survival >1 year (overall 60%). ConclusionsThis is the first detailed anatomic description of PIVSD in living patients. Defects may be larger in systole or diastole, meaning that single-phase measurement is unsuitable. Its complex nature means that the most commonly available occluder device is frequently unsuitable. Successful closure leads to prolonged survival and should be attempted where possible. This study may lead to improved patient selection, closure techniques, and device design.

The relationship between fragmented QRS complex and coronary collateral circulation in patients with chronic total occlusion lesion without prior myocardial infarction

Objective: To explore the relationship between fragmented QRS complex(fQRS) and coronary collateral circulation(CCC) in patients with chronic total occlusion(CTO)lesion without prior myocardial infarction. Methods: This retrospective study analyzed 238 consecutive patients with CTO lesion in one of the major coronary arteries from May 2014 to October 2015 in our department. Patients were divided into poor CCC group (grade 0 and 1, 58 cases) and good CCC group(grade 2 and 3, 180 cases) based on Rentrop's classification of CCC. The fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous electrocardiogram leads corresponding to a major coronary artery territory. Multivariate logistic regression was used to analyze the relationship between CCC and fQRS on electrocardiogram. Results: Compared with good CCC group, patients in poor CCC group had older age((65.2±8.9)years old vs. (60.3±10.1) years old, P=0.03), higher plasma glucose ((7.22±3.00) mmol/L vs.(6.31±1.83)mmol/L, P=0.04), and lower left ventricular ejection fraction ((45.2±11.4)% vs. (51.2±13.5)%, P=0.02). None of patients had Rentrop grade 0, the presence of fQRS on ECG in patients with Rentrop grade 1, grade 2, and grade 3 CCC was 69.0% (40/58), 48.6% (35/72) , and 19.4% (21/108), respectively (P<0.01). The presence of fQRS were higher in poor CCC group than in good CCC group (69.0%(40/58)vs. 31.1%(56/180), P<0.01), and number of leads with fQRS were higher in poor CCC group than in good CCC group (3(0, 4)vs.0(0, 3), P<0.01). Multivariate logistic regression analysis demonstrated that poor CCC growth in patients with CTO lesion without prior myocardial infarction was independently related to the presence of fQRS (OR=3.659, 95%CI 1.619-8.217, P<0.01). Conclusion: Poor CCC in patients with CTO lesion without prior myocardial infarction is independently related to the presence of fQRS on electrocardiogram.

Do Flow and Pulsatility Index within the Accepted Ranges Predict Long-Term Outcomes after Coronary Artery Bypass Grafting?

Transit-time flow measurement (TTFM) is the gold standard for intraoperative detection of graft failure. Several reports show that TTFM and distal coronary bed quality (DCBQ) may also be useful for midterm detection of graft failure. Nonetheless, there are no data regarding their predictive role on long-term outcomes. Patients with three-vessel disease who underwent isolated coronary artery bypass grafting (CABG) in 2006 and received at least one graft to the left anterior descending artery (LAD) or to the first obtuse marginal (OM1) or posterior descending artery (PDA) were included. Baseline characteristics, mean graft flow, pulsatility index, and subjective impression of DCBQ for each coronary territory were collected. Long-term cardiovascular (CV) and overall survival, operative mortality, and new percutaneous coronary intervention (PCI) were evaluated. A total of 177 patients underwent isolated CABG. The OM1 was grafted in 131 patients, the LAD in 169 patients, and the PDA in 100 patients. Neither DQCB nor TTFM were predictors for new PCI. Independent predictors for overall survival were age, previous acute myocardial infarction (AMI), and DQCB of OM1 (odds ratio [OR] = 2.97; 95% confidence interval [CI]: 1.15-7.71). Age, previous AMI, and DCBQ of OM1 (OR = 2.5; 95% CI: 1.39-4.81) were independent predictors for CV survival. TTFM on patients with functioning grafts does not predict long-term survival or performance of new PCI. Subjective evaluation of distal coronary bed, especially of the OM1, has a strong impact on long-term outcomes.

Randomized comparison between provisional and routine kissing-balloon technique after main vessel crossover stenting for coronary bifurcation lesions.

We compared the myocardial ischemic burden of provisional and routine final kissing-balloon inflation (FKI) with the 1-stent strategy using a second-generation drug-eluting stent for coronary bifurcation lesions (CBL). There are no established guidelines for side branch (SB) intervention after main vessel stenting. In total, 113 CBL patients were randomized to receive different SB intervention strategies: provisional-FKI group (n=57; FKI only when SB flow was TIMI <3) and routine-FKI group (n=56; mandatory FKI with aggressive treatment until SB-residual stenosis <50%). Dipyridamole-stress myocardial perfusion scintigraphy with 99mTc was performed after 8months. The regional summed-difference score (r-SDS) was calculated according to the coronary territory. The primary endpoint included target vessel ischemia (TVI; r-SDS≥2) at 8months, whereas the clinical primary endpoint was major adverse cardiovascular events (MACE) at 3years. The percent (%) myocardial ischemia (100×SDS/68) was also calculated. At 8months, TVI was identified in 11 and 4% in the provisional-FKI and routine-FKI groups, respectively (p=0.226). SB-binary restenosis (48 vs. 4%, p<0.001) and myocardial ischemia at the SB territory (11 vs. 0%, p=0.030) were more common in the provisional-FKI group; however, in TVI patients, % myocardial ischemia (4.12±1.23% vs. 3.68±1.04%; p=0.677) did not significantly differ. Moderate/severe ischemia (>10% myocardial ischemia) was not observed in the target vessel in either group. Long-term cumulative MACE were similar between the groups (9 vs. 14%; p=0.358). Provisional-FKI according to TIMI-SB flow grade led to similar and acceptable myocardial ischemia, in comparison with routine-FKI, which may contribute to the identical long-term follow-up.

A prospective study of external stenting of saphenous vein grafts to the right coronary artery: the VEST II study.

External stents significantly reduce intimal hyperplasia and improve lumen uniformity and flow pattern in saphenous vein grafts (SVG) 1 year after coronary artery bypass grafting. However, recent studies have shown that at 1 year there is a lower patency of externally stented SVG to the right coronary artery (RCA) (55-60%) when compared to the left sided coronary arteries (85-90%). In the current study, we investigated whether avoidance of both fixation of the external stent to the anastomoses and the use of metal clips to ligate SVG side branches would improve the early patency of externally stented SVG to the RCA. Thirty patients received a SVG to the right territory supported with an external stent. Graft patency was confirmed at the end of surgery in all patients. The primary endpoint was SVG patency assessed by computed tomography angiography (CTA) at 3-6 months. Graft failure was defined as > 50% stenosis. Twenty-nine patients (96.6%) completed the follow up period and CT angiography data was available for a total of 43 SVGs, (29 supported and 14 unsupported SVGs) and 47 arterial grafts. Patency of stented SVGs was 86.2% (25/29 on CTA). All non-stented SVGs to the left territory were patent. Patency rates of the left internal mammary arteries and right internal mammary arteries grafts were 96.6% and 83.3%, respectively. Avoidance of both metallic clips to ligate side branches and of fixation of venous external support trial (VEST) stents to the anastomoses mark a significant improvement in patency of stented SVG to the right coronary territory.

Quantitative myocardial blush grade reserve during pharmacologic hyperaemia: a way to perform a real wireless fractional flow reserve measurement in patients with coronary artery disease and intermediate coronary lesions.

We investigated the relation between myocardial blush grade reserve (MBGreserve) and fractional flow reserve (FFR) measures. FFR is a marker of inducible myocardial ischaemia, which could guide percutaneous coronary intervention (PCI) and stent placement. However, it requires a pressure wire and is associated with additional costs and potential hazards. The aim of our study was to investigate the ability of MBG for the evaluation of functional significance in intermediate coronary lesions during pharmacologic hyperaemia. Fifty-six patients who underwent routine cardiac catheterisation for known or suspected coronary artery disease (CAD) and clinically indicated FFR measures in at least one coronary vessel were analysed. MBGreserve was assessed at baseline and during pharmacologic hyperaemia. Video densitometric parameters were then calculated by the ratio of maximal density (Gmax) and the time to reach maximum density (Tmax). Gmax/Tmax during hyperaemia divided by Gmax/Tmax at baseline provided the MBGreserve. A significant association was observed between MBGreserve and FFR. A cut-off value of MBGreserve=2.1 demonstrated sensitivity of 80% and specificity of 96% for the prediction of abnormal FFR of ≤0.8. MBGreserve increased in coronary territories that underwent PCI, reaching similarly high values compared to those observed in FFR-negative lesions. Quantitative MBGreserve is closely related to FFR measures and may obviate the need for pressure wire measurements in the interests of patient safety, time and costs.

Accuracy of myocardial perfusion imaging in detecting multivessel coronary artery disease: A cardiac CZT study

BackgroundMyocardial perfusion imaging (MPI) performed on traditional single-photon emission computed-tomography cameras has been shown to have a sub-optimal accuracy in detecting multivessel coronary artery disease (CAD). MethodsSix-hundred and ninety-five patients were submitted to MPI on a novel cadmium-zinc-telluride (CZT) camera and coronary angiography. A coronary stenosis >70% was considered obstructive. In every patient, the summed stress score (SSS) was computed. Moreover, the regional stress scores were also calculated for every coronary territory. ResultsFour-hundred and forty-one patients had obstructive CAD in one (28%), two (19%), or three (17%) vessels. At per-patient analysis, the SSS showed a significant accuracy in detecting obstructive CAD (AUC 0.87, P < .001). Specifically, its accuracy was maintained also in patients with double (AUC 0.83; P < .001) or triple-vessels disease (AUC 0.79, P < .001), where CZT was able to correctly identify CAD extent in 64% of patients. On a per-vessel basis, CZT confirmed its high accuracy in detecting obstructive CAD (AUC 0.88, P < .001), independently from the involved coronary vessel. ConclusionsMPI performed on a CZT camera is highly accurate in detecting obstructive CAD, independently from the coronary artery involved and the overall disease burden.

Coronary Artery Bypass Surgery in Diffuse Advanced Coronary Artery Disease: 1-Year Clinical and Angiographic Results

Proper treatment of patients with diffuse, severe coronary artery disease (CAD) is a challenge due to its complexity. Thus, data on the outcomes after coronary artery bypass graft (CABG) in this population is scarce. In this study, we aimed to determine the impact of CABG on the clinical and functional status, as well as graft patency in those individuals. Patients with severe and diffuse CAD who underwent incomplete CABG due to complex anatomy or extensive distal coronary involvement were evaluated preoperatively and 1 year after surgery. Postoperative coronary angiography was performed to evaluate graft patency. Graft occlusion was defined as the complete absence of opacification of the target vessel. Stratified analysis of graft occlusion was performed by graft type and territories, defined as left anterior descending artery (LAD), the left circumflex branch, and the right coronary artery territories; the latter two, grouped, were further classified as non-LAD territory. A total of 57 patients were included, in whom 131 grafts were placed. There was a significant improvement in Canadian Cardiovascular Society angina symptom severity (Z = -6.1; p < 0.001) and maximum oxygen uptake (p < 0.001), with a corresponding decrease in the use of long-acting nitrates (p < 0.001). The overall graft occlusion rate was 19.1%, with no significant difference between LAD and non-LAD territories (p = 0.08). However, a significantly lower occlusion rate was noted for the internal mammary artery (IMA) grafts when compared with saphenous vein grafts (p = 0.01), though this difference was only significant in the LAD territory (p = 0.04). Overall, the use of venous graft was the only predictor occlusion at 1 year (odds ratio: 4.03; p = 0.016). In patients with diffuse CAD, incomplete CABG surgery resulted in a significant clinical improvement, with acceptable graft occlusion rates at 1 year, particularly for IMA grafts to the LAD territory.

Myocardial segmentation based on coronary anatomy using coronary computed tomography angiography: Development and validation in a pig model.

To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA). Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns. CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p < 0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p < 0.001) and mid- (99% vs. 83%; p = 0.046) and apical-level territories of the left ventricle (90% vs. 52%; p = 0.011). CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA. • CAMS is a feasible method for identifying corresponding coronary territory using CTA • CAMS is more accurate in predicting coronary territory than the AHA method • The AHA method may underestimate the ischaemic territory of LAD stenosis.

Evaluation of Coronary Artery Disease Using Myocardial Elastography with Diverging Wave Imaging: Validation against Myocardial Perfusion Imaging and Coronary Angiography

Myocardial elastography (ME) is an ultrasound-based technique that can image 2-D myocardial strains. The objectives of this study were to illustrate that 2-D myocardial strains can be imaged with diverging wave imaging and differ, on average, between normal and coronary artery disease (CAD) patients. In this study, 66 patients with symptoms of CAD were imaged with myocardial elastography before a nuclear stress test or an invasive coronary angiography. Radial cumulative strains were estimated in all patients. The end-systolic radial strain in the total cross section of the myocardium was significantly higher in normal patients (17.9 ± 8.7%) than in patients with reversible perfusion defect (6.2 ± 9.3%, p < 0.001) and patients with significant (−0.9 ± 7.4%, p < 0.001) and non-significant (3.7 ± 5.7%, p < 0.01) lesions. End-systolic radial strain in the left anterior descending, left circumflex and right coronary artery territory was found to be significantly higher in normal patients than in CAD patients. These preliminary findings indicate that end-systolic radial strain measured with ME is higher on average in healthy persons than in CAD patients and that ME has the potential to be used for non-invasive, radiation-free early detection of CAD.

Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function.

ObjectiveWe sought to determine the prognostic value of qualitative and quantitative analysis obtained by real-time myocardial perfusion echocardiography (RTMPE) in patients with known or suspected coronary artery disease (CAD).BackgroundQuantification of myocardial blood flow reserve (MBFR) in patients with CAD using RTMPE has been demonstrated to further improve accuracy over the analysis of wall motion (WM) and qualitative analysis of myocardial perfusion (QMP).MethodsFrom March 2003 to December 2008, we prospectively studied 168 patients with normal left ventricular function (LVF) who underwent dobutamine stress RTMPE. The replenishment velocity reserve (β) and MBFR were derived from RTMPE. Acute coronary events were: cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization.ResultsDuring a median follow-up of 34 months (5 days to 6.9 years), 17 acute coronary events occurred. Abnormal β reserve in ≥2 coronary territories was the only independent predictor of events hazard ratio (HR) = 21, 95% CI = 4.5–99; p<0.001). Both, abnormal β reserve and MBFR added significant incremental value in predicting events over qualitative analysis of WM and MP (χ2 = 6.6 and χ2 = 24.6, respectively; p = 0.001 and χ2 = 6.6 and χ2 = 15.5, respectively; p = 0.012, respectively). When coronary angiographic data was added to the multivariate analysis model, β reserve remained the only predictor of events with HR of 21.0 (95% CI = 4.5–99); p<0.001.ConclusionQuantitative dobutamine stress RTMPE provides incremental prognostic information over clinical variables, qualitative analysis of WM and MP, and coronary angiography in predicting acute coronary events.

Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and 99mTc-tetrofosmin: Method and validation

BackgroundThe objective of this study was to measure myocardial blood flow (MBF) in humans using 99mTc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). MethodsDynamic SPECT using 99mTc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99mTc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99mTc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curve K1=F1-Aexp-BF for K1 values estimated with 99mTc-tefrofosmin using SPECT and MBF values estimated with 13N-NH3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13N-NH3 PET. The flow-dependent permeability surface-area product (PS) for 99mTc-tefrofosmin was also estimated. ResultsThe estimated flow-extraction parameters for 99mTc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R2 = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for 99mTc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16). ConclusionsDynamic cardiac SPECT using 99mTc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.

Relationship between gated myocardial perfusion SPECT findings and hemodynamic, electrocardiographic, and heart rate changes after Dipyridamole infusion.

After dipyridamole infusion, electrocardiographic (ECG), blood pressure and heart rate (HR) changes were seen. We tried to investigate whether there is a relationship between hemodynamic, ECG and HR changes after dipyridamole infusion and gated myocardial perfusion SPECT findings. We studied 206 consecutive patients which underwent a 2-day protocol Dipyridamole Stress/Rest Tc99m-Sestamibi gated myocardial perfusion SPECT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and ECG were recorded. HR was mildly increased while SBP and DBP were mildly decreased after Dipyridamole infusion. There was only statistically significant difference between ECG changes as well as transient ischemic dilation (TID) ratio between normal scans and scans with ischemia (P = 0.02 and P = 0.01 respectively). There was correlation between these variables and summed stress score (SSS) and summed difference score (SDS). Patients with ischemia in their scans, 44.3% had ST depression after Dipyridamole infusion. Also ST depression most frequently was seen in patients with left anterior descending artery disease. From patients with abnormal scan + ST depression after Dipyridamole infusion (33 patient), 27 patient (81.81%) had ischemia. There was an association between TID ratio as well as ECG changes after Dipyridamole infusion and SSS, SDS and coronary artery territory abnormality. Difference between calculated left ventricular ejection fraction using stress and rest images had significant correlation with SSS and SDS. ST depression after Dipyridamole infusion and TID ratio had association with ischemia, SSS and SDS. So in equivocal Gated SPECT findings, they could be very useful for interpretation.

The Systematic Evaluation of Identifying the Infarct Related Artery Utilizing Cardiac Magnetic Resonance in Patients Presenting with ST-Elevation Myocardial Infarction.

BackgroundIdentification of the infarct-related artery (IRA) in patients with STEMI using coronary angiography (CA) is often based on the ECG and can be challenging in patients with severe multi-vessel disease. The current study aimed to determine how often percutaneous intervention (PCI) is performed in a coronary artery different from the artery supplying the territory of acute infarction on cardiac magnetic resonance imaging (CMR).MethodsWe evaluated 113 patients from the Reduction of infarct Expansion and Ventricular remodeling with Erythropoetin After Large myocardial infarction (REVEAL) trial, who underwent CMR within 4±2 days of revascularization. Blinded reviewers interpreted CA to determine the IRA and CMR to determine the location of infarction on a 17-segment model. In patients with multiple infarcts on CMR, acuity was determined with T2-weighted imaging and/or evidence of microvascular obstruction.ResultsA total of 5 (4%) patients were found to have a mismatch between the IRA identified on CMR and CA. In 4/5 cases, there were multiple infarcts noted on CMR. Thirteen patients (11.5%) had multiple infarcts in separate territories on CMR with 4 patients (3.5%) having multiple acute infarcts and 9 patients (8%) having both acute and chronic infarcts.ConclusionsIn this select population of patients, the identification of the IRA by CA was incorrect in 4% of patients presenting with STEMI. Four patients with a mismatch had an acute infarction in more than one coronary artery territory on CMR. The role of CMR in patients presenting with STEMI with multi-vessel disease on CA deserves further investigation.

Quantitative myocardial blood flow imaging with integrated time-of-flight PET-MR

BackgroundThe use of integrated PET-MR offers new opportunities for comprehensive assessment of cardiac morphology and function. However, little is known on the quantitative accuracy of cardiac PET imaging with integrated time-of-flight PET-MR. The aim of the present work was to validate the GE Signa PET-MR scanner for quantitative cardiac PET perfusion imaging. Eleven patients (nine male; mean age 59 years; range 46–74 years) with known or suspected coronary artery disease underwent 15O-water PET scans at rest and during adenosine-induced hyperaemia on a GE Discovery ST PET-CT and a GE Signa PET-MR scanner. PET-MR images were reconstructed using settings recommended by the manufacturer, including time-of-flight (TOF). Data were analysed semi-automatically using Cardiac VUer software, resulting in both parametric myocardial blood flow (MBF) images and segment-based MBF values. Correlation and agreement between PET-CT-based and PET-MR-based MBF values for all three coronary artery territories were assessed using regression analysis and intra-class correlation coefficients (ICC). In addition to the cardiac PET-MR reconstruction protocol as recommended by the manufacturer, comparisons were made using a PET-CT resolution-matched reconstruction protocol both without and with TOF to assess the effect of time-of-flight and reconstruction parameters on quantitative MBF values.ResultsStress MBF data from one patient was excluded due to movement during the PET-CT scanning. Mean MBF values at rest and stress were (0.92 ± 0.12) and (2.74 ± 1.37) mL/g/min for PET-CT and (0.90 ± 0.23) and (2.65 ± 1.15) mL/g/min for PET-MR (p = 0.33 and p = 0.74). ICC between PET-CT-based and PET-MR-based regional MBF was 0.98. Image quality was improved with PET-MR as compared to PET-CT. ICC between PET-MR-based regional MBF with and without TOF and using different filter and reconstruction settings was 1.00.ConclusionsPET-MR-based MBF values correlated well with PET-CT-based MBF values and the parametric PET-MR images were excellent. TOF and reconstruction settings had little impact on MBF values.

Outcome of coronary endarterectomy with coronary artery bypass grafting in patients with diffuse coronary artery disease in Bangladesh: A retrospective cohort study.

BackgroundIn this study, we aimed to review the consequences of coronary endarterectomy with coronary artery bypass grafting, and assess outcomes of this combined surgical technique for patients with diffuse coronary artery disease in a single surgeon’s practice.MethodsWe retrospectively reviewed outcome of 1198 endarterectomized coronary artery in 1000 patients with diffuse coronary artery disease, who have had experienced coronary endarterectomy with off pump coronary artery bypass grafting in between 2009 and 2016.ResultsThe mean age was 61.5 ± 5.5 years. Coronary endarterectomy was performed on 74.7% in the left coronary territory (43.2% left anterior descending, 26.6% diagonal, 4.9% Obtuse Marginal), and 25.3% in the right coronary territory. Post-operative intensive care unit mortality rate was 1.9%, and there were 11 (1.1%) late deaths. Mean intensive care unit stay was 36.6 ± 6.7 hours. Patients were extubated following a mean of 9.8 ± 1.25 hours. The mean duration of hospital stay was 10 ± 1 days. One-year survival rate was 97.8% and 89.5% survival rate was at 5 years follow up. However, 91.8% of patients were angina free at median follow-up of 2.5 years.ConclusionCoronary endarterectomy with off pump coronary artery bypass grafting is attainable and accomplishes surgical revascularization in coronary artery disease patients when there is no other alternative for sufficient revascularization.

Coronary Artery Bypass Grafting in a Patient With Dextrocardia and Situs Inversus

Situs inversus is a rare congenital abnormality affecting approximately 1/10,000 patients where the position of the major organs are reversed. Situs inversus with dextrocardia involves malposition of the heart with the cardiac mass lying to the right of the midline with the apex also oriented to the right rather than its usual leftward orientation. This presents a unique challenge when such patients require coronary artery bypass surgery (CABG) with respect to cannulation technique for cardiopulmonary bypass, choice of graft conduits, graft configuration and where the surgeon stands when operating. A variety of strategies for CABG in patients with dextrocardia have been described with significant variation in operative strategies reported. We present the case of a 74-year-old male with dextrocardia and situs inversus presenting with exertional angina and a positive stress test who was referred for CABG after a coronary angiogram revealed 3-vessel coronary artery disease. After median sternotomy the RIMA was harvested with the surgeon standing to the patient's left. The surgeon then changed position to the conventional right side for cannulation for bypass due to their comfort and familiarity with using their right hand for cannulation. Standard aortic and 2-stage venous cannulas were used to establish cardiopulmonary bypass. The surgeon then completed the operation from the left side of the patient with the RIMA anastomosed to the LAD and saphenous vein to the circumflex and right coronary territories. The patient recovered well and at 6-week follow-up was pain free without significant complication. This case highlights the flexibility in operative strategy needed for CABG in patients with dextrocardia and situs inversus.

Relationship between fragmented QRS complexes in leads V4-V6 and left ventricular apical thrombus formation in patients presenting with first acute anterior myocardial infarction.

The present study was an investigation of the relationship between fragmented QRS (fQRS) and left ventricular apical thrombus (LVAT) in patients presenting with first acute anterior myocardial infarction (MI). Consecutive 148 patients (mean age: 60.1±10.1 years; male: 75.6%) with first acute anterior MI who underwent primary percutaneous coronary intervention (PCI) were included. Study population was divided into 2 groups based on presence of LVAT. fQRS was defined as presence of various RSR' patterns, which included additional R wave or notching of R wave or S wave, and presence of more than 1 R in 2 contiguous leads corresponding to major coronary artery territory on 12-lead electrocardiogram. Patients with bundle branch block were excluded from the study. Of these, 32 (21.6%) had LVAT. Patients with LVAT had higher prevalence of fQRS (53.1% vs. 22.4%; p<0.001) and lower rate of successful PCI (75% vs. 94%; p=0.002) compared with patients without LVAT. More patients in LVAT group had left ventricular ejection fraction of <30% (87.5% vs 65.5%; p=0.010). Groups were similar with respect to other baseline characteristics (p>0.05 for all). Presence of fQRS was independent predictor of LVAT (odds ratio [OR], 2.795; 95% confidence interval [CI], 1.058-7.396) in multivariable logistic regression analysis. Presence of fQRS in leads V4-V6 is independently associated with LVAT in patients presenting with first acute anterior MI.

QRS Fragmentation Patterns Representing Myocardial Scar Need to Be Separated from Benign Normal Variants: Hypotheses and Proposal for Morphology based Classification.

The presence of a fragmented QRS complex (fQRS) in two contiguous leads of a standard 12-lead electrocardiogram (ECG) has been shown to be an indicator of myocardial scar in multiple different populations of cardiac patients. QRS fragmentation is also a predictor of adverse prognosis in acute myocardial infarction, coronary artery disease, and ischemic cardiomyopathy and a prognostic tool in structural heart diseases. An increased risk of sudden cardiac death associated with fQRS has been documented in patients with ischemic cardiomyopathy and hypertrophic cardiomyopathy. However, fQRS is also frequently observed in apparently healthy subjects. Thus, a more detailed classification of different QRS fragmentations is needed to identify the pathological fragmentation patterns and refine the role of fQRS as a risk marker of adverse cardiac events and sudden cardiac death. In most studies fQRS has been defined by the presence of an additional R wave (R′), or notching in the nadir of the S wave, or the presence of >1 R′ in two contiguous leads corresponding to a major coronary territory. However, this approach does not discriminate between minor and major fragmentations and the location of the fQRS is also neglected. In addition to this, the method is susceptible to large interobserver variability. We suppose that some fQRS subtypes result from conduction delays in the His-Purkinje system, which is a benign finding and thus can weaken the prognostic values of fQRS. The classification of fQRSs to subtypes with unambiguous definitions is needed to overcome the interobserver variability related issues and to separate fQRSs caused by myocardial scarring from benign normal variants. In this paper, we review the anatomic correlates of fQRS and the current knowledge of prognostic significance of fQRS. We also propose a detailed fQRS classification for research purposes which can later be simplified after the truly pathological morphologies have been identified. The research material of our study consist of 15,245 ECGs from the random general population and approximately six thousands (n = 6,241) ECGs from subjects with a known cardiac disease.