Evaluation of fractional flow reserve and atherosclerotic plaque characteristics on coronary non-contrast T1-weighted magnetic resonance imaging

BACKGROUND AND AIMS

The relationship between high-risk coronary plaque characteristics regardless of the severity of lesion stenosis and myocardial ischemia remains unsettled. High-intensity plaques (HIPs) on non-contrast T1-weighted magnetic resonance imaging (T1WI) have been characterized as high-risk coronary plaques. We sought to elucidate whether the presence of coronary HIPs on T1WI influences fractional flow reserve (FFR) in the distal segment of the vessel.

METHODS

We retrospectively analyzed 281 vessels in 231 patients with chronic coronary syndrome who underwent invasive FFR measurement and coronary T1WI using a multicenter registry. The plaque-to-myocardial signal intensity ratio (PMR) of the most stenotic lesion was evaluated; a coronary plaque with PMR ≥1.4 was defined as a HIP.

RESULTS

The median PMR of coronary plaques on T1WI in vessels with FFR ≤0.80 was significantly higher than that of plaques with FFR >0.80 (1.17 [interquartile range (IQR): 0.99-1.44] vs. 0.97 [IQR: 0.85-1.09]; p < 0.001). Multivariable analysis showed that an increase in PMR of the most stenotic segment was associated with lower FFR (beta-coefficient, -0.050; p < 0.001). The presence of coronary HIPs was an independent predictor of FFR ≤0.80 (odds ratio (OR), 6.18; 95% confidence interval (CI), 1.93-19.77; p = 0.002). Even after adjusting for plaque composition characteristics based on computed tomography angiography, the presence of coronary HIPs was an independent predictor of FFR ≤0.80 (OR, 4.48; 95% CI, 1.19-16.80; p = 0.026).

CONCLUSIONS

Coronary plaques with high PMR are associated with low FFR in the corresponding vessel, indicating that plaque morphology might influence myocardial ischemia severity.

Initial results of transcatheter modification of left atrial appendage by obliteration with device in patients with nonvalvular atrial fibrillation: Real-world data from the TERMINATOR registry

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has increased for those who need alternative to long-term anticoagulation with non-valvular atrial fibrillation (NVAF).

METHODS AND RESULTS

From September 2019, after initiating WATCHMAN (Boston Scientific, Maple Grove, MN, USA) device implantation, we established Transcatheter Modification of Left Atrial Appendage by Obliteration with Device in Patients from the NVAF (TERMINATOR) registry. Utilizing 729 patients' data until January 2022, we analyzed percutaneous LAAC data regarding this real-world multicenter prospective registry. A total of 729 patients were enrolled. Average age was 74.9 years and 28.5 % were female. Paroxysmal AF was 37.9 % with average CHADS2 3.2, CHA2DS2-VASc 4.7, and HAS-BLED score of 3.4. WATCHMAN implantation was successful in 99.0 %. All-cause deaths were 3.2 %, and 1.2 % cardiovascular or unexplained deaths occurred during follow-up [median 222, interquartile range (IQR: 93-464) days]. Stroke occurred in 2.2 %, and the composite endpoint which included cardiovascular or unexplained death, stroke, and systemic embolism were counted as 3.4 % [median 221, (IQR: 93-464) days]. Major bleeding defined as BARC type 3 or 5 was seen in 3.7 %, and there was 8.6 % of all bleeding events in total [median 219, (IQR: 93-464) days].

CONCLUSIONS

These preliminary data demonstrated percutaneous LAAC with WATCHMAN device might have a potential to reduce stroke and bleeding events for patients with NVAF. Further investigation is mandatory to confirm the long-term results of this strategy using this transcatheter local therapy instead of life-long systemic anticoagulation.

Calcified plaque harboring lipidic materials associates with no-reflow phenomenon after PCI in stable CAD

Calcified atheroma has been viewed conventionally as stable lesion which less likely increases no-reflow phenomenon. Given that lipidic materials triggers the formation of calcification, lipidic materials could exist within calcified lesion, which may cause no-reflow phenomenon after PCI. The REASSURE-NIRS registry (NCT04864171) employed near-infrared spectroscopy and intravascular ultrasound imaging to evaluate maximum 4-mm lipid-core burden index (maxLCBI4mm) at target lesions containing small (maximum calcification arc < 180°: n = 272) and large calcification (maximum calcification arc ≥ 180°: n = 189) in stable CAD patients. The associations of maxLCBI4mm with corrected TIMI frame count (CTFC) and no-reflow phenomenon after PCI were analyzed in patients with target lesions containing small and large calcification, respectively. No-reflow phenomenon occurred in 8.0% of study population. Receiver-operating characteristics curve analyses revealed that optimal cut-off values of maxLCBI4mm for predicting no-reflow phenomenon were 585 at small calcification (AUC = 0.72, p < 0.001) and 679 at large calcification (AUC = 0.76, p = 0.001). Target lesions containing small calcification with maxLCBI4mm ≥ 585 more likely exhibited a greater CTFC (p < 0.001). In those with large calcification, 55.6% of them had maxLCBI4mm ≥ 400 [vs. 56.2% (small calcification), p = 0.82]. Furthermore, a higher CTFC (p < 0.001) was observed in association with maxLCBI4mm ≥ 679 at large calcification. On multivariable analysis, maxLCBI4mm at large calcification still independently predicted no-reflow phenomenon (OR = 1.60, 95%CI = 1.32-1.94, p < 0.001). MaxLCBI4mm at target lesions exhibiting large calcification elevated a risk of no-reflow phenomenon after PCI. Calcified plaque containing lipidic materials is not necessarily stable lesion, but could be active and high-risk one causing no-reflow phenomenon.

Unexpected deformation of the right coronary artery during percutaneous coronary intervention with venoarterial extracorporeal membrane oxygenation combined with Impella: a case report

Background

The establishment of cautionary notes regarding percutaneous coronary intervention (PCI) with venoarterial extracorporeal membrane oxygenation combined with Impella (ECMELLA) is still lacking.

Case summary

A 68-year-old man was transferred to our hospital with cardiac arrest. ECMELLA insertion was performed via the bilateral femoral artery and vein for refractory ventricular fibrillation. Coronary angiography revealed an occluded lesion in the right coronary artery (RCA). Contrast injection was administered after confirming backflow through the guide catheter (GC) to avoid coronary dissection because the artery pressure was non-pulsatile during total circulation support. Prudent coronary angiography revealed a couple of accordion phenomena. Additionally, coronary angiography showed a shorter distance from the right border of the cardiac silhouette to the RCA and the venous line of extracorporeal membrane oxygenation than before PCI. This drastic change in the cardiac silhouette suggested that ECMELLA induced the collapse of the right heart system. Subsequently, a drug-eluting stent was implanted successfully. Final coronary angiography confirmed severe bending in the proximal segment of the RCA, which was absent in the reference coronary angiography. The patient had an uneventful course except for mild cognitive impairment. The computed tomography coronary angiography after ECMELLA removal indicated the RCA without deformation.

Discussion

In the present case, the collapse of the right heart system caused by ECMELLA resulted in RCA deformation. This case also underscored that contrast injection to the coronary artery in total circulation support should be administered after confirmation of backflow through a GC.

Pulmonary hypertension secondary to interstitial fibrosis with pulmonary venous lesions masquerading pulmonary veno-occlusive disease

We present a 41-year-old man with idiopathic interstitial pneumonia and pulmonary hypertension (PH) in the setting of a non-autoimmune background whose clinical presentation masqueraded pulmonary veno-occlusive disease (PVOD). Because of no histological evidence of venous occlusion in his previous lung biopsy, phosphodiesterase type-5 inhibitor was given, resulting in sudden onset of pulmonary edema. At autopsy, there were histological features of interstitial fibrosis with occlusion of the lobular septal veins and venules. Clinical presentations of PH due to interstitial fibrosis with pulmonary venous lesions may simulate those of PVOD and careful diagnostic and therapeutic approaches are required.

Intracardiac Thrombosis and Systemic Embolism in a Patient with Cardiac Amyloidosis in Sinus Rhythm

Intracardiac thrombosis formation in patients in sinus rhythm is a rare phenomenon. An 84-year-old woman was admitted because of worsening dyspnea on exertion. An electrocardiogram showed sinus rhythm, left atrial overload, marked left axis deviation, low voltage, and poor r-wave progression in leads V1-4. An echocardiogram showed relatively preserved left ventricular ejection fraction with minimal wall thickening. Her serum level of B-type natriuretic peptide (931 pg/mL) was markedly elevated and a diagnosis of worsening heart failure was made. During the course of treatment for heart failure, she was complicated by acute abdominal aortic thromboembolism together with left atrial thrombus. An emergency abdominal aortic thrombectomy was followed by the removal of a left atrial thrombus 2 days later. Left ventricular biopsy performed during the surgery revealed amyloid deposits in the myocardial interstitium. Immunohistochemical study confirmed the diagnosis of transthyretin cardiac amyloidosis. It is postulated that the risk of intracardiac thrombosis and systemic embolism is increased even in sinus rhythm in patients with cardiac amyloidosis.

Unilateral Pulmonary Edema in Patients With Acute Mitral Regurgitation Caused by Chordal Rupture

Background: Cardiogenic unilateral pulmonary edema (UPE) has been reported as an unusual condition and to occur in association with severe mitral regurgitation (MR). However, the prevalence of UPE in patients with severe MR remains unknown. Methods and Results: Among 143 consecutive patients with chordal rupture and significant MR, 38 patients with acute severe MR were studied. The prevalence of UPE was 50% (19 patients); all these patients had right-sided UPE. Eight (21%) patients had bilateral pulmonary edema (BPE). All 8 patients with BPE and 18 of 19 patients with UPE had chordal rupture of the posterior leaflet. All patients with UPE and BPE had severe MR with similar left atrial size. Chest radiographs taken ≤48 h from symptom onset diagnosed UPE in 15 of 19 (79%) patients and BPE in 3 of 8 (38%) patients (P=0.037). Chest radiographs taken >48 h from symptom onset diagnosed UPE in 4 (21%) patients and BPE in 5 (62%) patients (P=0.037). Conclusions: The prevalence of UPE was estimated as 50%; it was most frequently right sided and almost always associated with chordal rupture of the posterior leaflet. UPE is not rare, but common, particularly shortly after the development of acute severe MR caused by chordal rupture.

Acute Left Circumflex Coronary Artery Occlusion ― Diagnostic Problems of Initial Electrocardiographic Changes ―

Background: Acute coronary syndrome (ACS) with occlusion of the left circumflex coronary artery (LCX) poses diagnostic problems that may lead to a delay in reperfusion.

Methods and Results: From a group of 1,269 consecutive patients with ACS, 138 patients with ACS due to LCX occlusion were analyzed for clinical, electrocardiographic, and angiographic presentations, as well as door-to-balloon (DTB) time. Electrocardiographic changes were classified into 4 patterns: ST-segment elevation in inferior/lateral leads (ST-E); ST-segment depression in V1–V4 (ST-D); no significant ST changes (No-ST); and others. The No-ST group was associated with a longer DTB time (P<0.0001) compared with the ST-E and ST-D groups. Compared with the No-ST and ST-E groups, the ST-D group presented with a more advanced Killip class (P=0.003), greater peak creatine phosphokinase (P=0.007) and peak creatine kinase-MB (P=0.006), more frequent proximal LCX occlusion (P=0.007), and worse 1-year outcomes (P=0.0034).

Conclusions: One-third of ACS patients with LCX occlusion showed no ST-segment changes, resulting in significantly longer DTB time. Improving diagnostic accuracy is challenging but critical to avoid delayed reperfusion in these patients without electrocardiographic changes.

Acute circumflex coronary artery occlusion; dilemma in diagnosis and management

Background

Acute coronary syndrome (ACS) with occlusion of the circumflex coronary artery (LCX) poses diagnostic dilemma that may lead to a delay in reperfusion.

Purpose

We sought to assess the diagnostic significance of initial electrocardiography (ECG) changes in patients with acute LCX occlusion in relation to its clinical characteristics and the management.

Methods

From consecutive 1269 patients with ACS who were admitted to our institution during a 5-year period (2015–2019), 138 patients with ACS due to LCX occlusion were analyzed for clinical, ECG and angiographic presentation, and the door-to-balloon (DTB) time. ECG changes were classified into 4 different patterns: 1) ST-elevation in inferior/lateral leads (ST-E); 2) ST-depression in V1-V4 (ST-D); 3) no significant ST changes (No-ST); and 4) others.

Results

(1) No-ST pattern was found in 47 patients (34%), ST-E in 47 patients (34%), ST-D in 25 patients (18%) and others in 19 patients (14%). (2) Occlusion site: Proximal LCX; 16 patients with No-ST (34%), 6 patients with ST-E (13%), 13 patients with ST-D (52%). Distal LCX; 28 patients with No-ST (60%), 35 patients with ST-E (74%), 11 patients with ST-D (44%) (p=0.007). (Table) (3) Echocardiographic identification of left ventricular asynergy; 31 patients with No-ST (66%), 38 patients with ST-E (81%), 22 patients with ST-D (88%). (4) No-ST group was associated with longer DTB time; 245 min (170–562 min), compared to 93 min (83–121 min) in ST-E group and 97 min (70–129 min) in ST-D group (p&lt;0.0001). DTB time ≤90 min was significantly uncommon in No-ST group (11%), compared to ST-E group (46%) and ST-D group (43%) (p=0.0004). (Figure)

Conclusion

One-third of the patients with LCX-ACS showed no ST changes, resulting in significantly longer DTB time. Improving diagnostic accuracy with anticipation for LCX-ACS and the use of echocardiographic examination and also the possible application of posterior leads (V7-V9) recording is challenging but critical to avoid delayed reperfusion and to improve outcomes in these patients without ECG changes.

Funding Acknowledgement

Type of funding sources: None.

Cardiac outcomes in patients with acute coronary syndrome attributable to calcified nodule

BACKGROUND AND AIMS

Calcified nodule (CN) is an eruptive calcified mass causing acute coronary syndrome (ACS). Since coronary calcification is associated with an elevated cardiac event's risk, ACS attributable to CN may exhibit worse clinical outcome following percutaneous coronary intervention (PCI).

METHODS

We retrospectively analyzed 657 ACS patients receiving PCI with newer-generation drug-eluting stent (DES) implantation under intravascular ultrasound (IVUS) guidance. CN was defined as (1) protruding calcification with its irregular surface and (2) the presence of calcification at adjacent proximal and distal segments. The primary endpoint was a composite of major adverse cardiac event [MACE = cardiac death + ACS recurrence + target lesion revascularization (TLR)].

RESULTS

CN was identified in 5.3% (=35/657) of the study subjects. CN patients were more likely to have coronary risk factors including hypertension (p = 0.005), chronic kidney disease (p < 0.001), maintenance hemodialysis (p < 0.001) and a history of PCI (p < 0.001). During the observational period (median = 1304 days), CN was associated with an increased risk of MACE (HR = 7.68, 95%CI = 4.61-12.80, p < 0.001), ACS recurrence (HR = 12.32, 95%CI = 6.05-25.11, p < 0.001) and TLR (HR = 10.48, 95%CI = 5.80-18.94, p < 0.001). These cardiac risks related to CN were consistently observed by Cox proportional hazards model (MACE: p < 0.001, ACS recurrence: p < 0.001, TLR: p < 0.001) and a propensity score-matched cohort analysis (MACE: p = 0.002, ACS recurrence: p = 0.01, TLR: p = 0.005). Of note, over 80% of TLR at the CN lesion was driven by its re-appearance within the implanted DES.

CONCLUSIONS

ACS patients attributable to CN have an increased risk of ACS recurrence and TLR, mainly driven by the continuous growth and protrusion of the calcified mass.

In vivo imaging of vulnerable plaque with intravascular modalities: its advantages and limitations

In vivo imaging of plaque instability has been considered to have a great potential to predict future coronary events and evaluate the stabilization effect of novel anti-atherosclerotic medical therapies. Currently, there are several intravascular imaging modalities which enable to visualize plaque components associated with its vulnerability. These include virtual histology intravascular ultrasound (VH-IVUS), integrated backscatter IVUS (IB-IVUS), optical coherence tomography (OCT), near-infrared spectroscopy and coronary angioscopy. Recent studies have shown that these tools are applicable for risk stratification of cardiovascular events as well as drug efficacy assessment. However, several limitation exists in each modality. The current review paper will outline advantages and limitation of VH-IVUS, IB-IVUS, OCT, NIRS and coronary angioscopy imaging.

Cholesterol-crystalized coronary atheroma as a potential precursor lesion causing acute coronary syndrome: a case report

Background

Histopathological studies have reported the presence of cholesterol crystals in the culprit lesion in patients with sudden cardiac death. Given that cholesterol crystals themselves promote pro-inflammatory cascades, they may destabilize atherosclerotic plaques, leading to the occurrence of acute coronary events.

Case summary

A 60-year-old man presented with ST-segment elevation myocardial infarction. Emergent coronary angiography revealed a severely stenotic lesion (=culprit lesion) and another non-obstructive lesion in the proximal and middle segments of the left anterior descending artery (LAD), respectively. Optical coherence tomography (OCT) imaging showed that both lesions exhibited lipid-rich plaque with cholesterol crystals, and the non-obstructive lesion in the mid-LAD did not have a thin fibrous cap (its thickness = 230 μm). A drug-eluting stent was successfully implanted at the culprit lesion in the proximal LAD. On non-contrast T1-weighted magnetic resonance imaging performed 10 days after percutaneous coronary intervention (PCI), a high-intensity signal was identified at the non-obstructive mid-LAD lesion. This lesion was medically managed with aspirin, clopidogrel, and rosuvastatin due to the absence of myocardial ischaemia. However, 12 months after PCI, the patient was hospitalized again due to unstable angina pectoris. Coronary angiography revealed substantial progression of the mid-LAD lesion. Optical coherence tomography imaging prior to the second PCI showed a severely narrowed lesion containing cholesterol crystals and covered by organized thrombus. This lesion harbored an extensive amount of lipidic materials on near-infrared spectroscopy (maximum 4-mm lipid core burden index = 809).

Discussion

In our case, atherosclerotic plaques containing cholesterol crystals was associated with the occurrence of acute coronary syndrome. Our findings suggest that plaque with cholesterol crystals is a potential precursor to future acute coronary events.

Primary Cardiac Lymphoma: A Lesson Learned from an Unsuccessful Experience

A 79-year-old man was admitted because of complete heart block. Echocardiograms showed an abnormal mass adjacent to the sinus of Valsalva. Subsequent surgical resection was not successful. Despite chemotherapy, the patient died from multiple organ failure. It is important to recognize that approximately 80% of cases of cardiac lymphoma are diffuse large B-cell lymphoma, which is the only malignant neoplasm that may respond well to chemotherapy with rituximab. In order to save patients' lives, the early implementation of chemotherapy with rituximab is critical and should be considered as a therapeutic diagnostic option in select patients.

Comparison of Long-Term Mortality in Patients With Previous Coronary Artery Bypass Grafting Who Underwent Percutaneous Coronary Intervention With Versus Without Optimal Medical Therapy

Although current guidelines have highlighted the importance of evidence-based optimal medical therapy (OMT) in patients with previous coronary artery bypass grafting (CABG), the effect of OMT on post-CABG patients requiring secondary coronary revascularization on prognosis remains unknown. We sought to examine the impact of OMT on post-CABG patients who underwent percutaneous coronary intervention (PCI) as secondary revascularization. A total of 632 consecutive post-CABG patients who underwent PCI between 2001 and 2013 at our hospital (84% men, median age 71 years) were divided into 2 groups: patients who were discharged with OMT and patients who were discharged without OMT (non-OMT). OMT was defined as the combination of an antiplatelet agent, statin, β blocker, and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Despite having a higher prevalence of clinical comorbidities, patients with OMT (n = 163) had a lower prevalence of all-cause death than those without OMT (n = 469) during a median follow-up of 95 months (OMT group 21.5%, non-OMT group 34.1%, p = 0.002). Both groups had similar procedural success rates. In a propensity-matched cohort (n = 146 each), OMT was associated with lower rates of all-cause death and cardiac death than non-OMT 8 years after PCI. In multivariable analysis, OMT was an independent predictor of all-cause death (hazard ratio [HR] 0.49, 95% confidence interval [CI] 0.34 to 0.72, p <0.001). In conclusion, OMT plays a protective role and reduces all-cause death in post-CABG patients requiring subsequent PCI. Outside of the domain of coronary revascularization, OMT could be considered an essential treatment in this patient population.

Actions of tizanidine on alpha 1-and alpha 2-adrenoceptors in the peripheral tissues

Tizanidine behaved as the partial agonist on the alpha 1-adrenoceptor in high doses (10(-6) -10(-4)M) and as the alpha 2-adrenoceptor agonist in low doses (3 X 10(-9) - 10(-6)M). Tizanidine is about one-third as potent as clonidine in alpha 2-agonistic effect