Prognostic Impact of Echocardiographic Congestion Grade in HFpEF With and Without Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is common in heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

This study aimed to investigate the prognostic value of echocardiographic markers of congestion that can be applied to both AF and patients without AF with HFpEF.

METHODS

We conducted a multicenter study of 505 patients with HFpEF admitted to hospitals for acute decompensated heart failure. The ratio of early diastolic transmitral flow velocity to mitral annulus velocity (E/e'), the tricuspid regurgitation peak velocity, and the collapsibility of the inferior vena cava were obtained at discharge. Congestion was determined by echocardiography if any one of E/e' ≥14 (E/e' ≥11 for AF), tricuspid regurgitation peak velocity ≥2.8 m/s, or inferior vena cava collapsibility <50% was positive. We classified patients into grade A, grade B, and grade C according to the number of positive congestion indices. The primary endpoint was the composite of cardiovascular death and heart failure hospitalization.

RESULTS

During the follow-up period (median: 373 days), 162 (32%) patients experienced the primary endpoint. Grade C patients had a higher risk for the primary endpoint than grade A (HR: 2.98; 95% CI: 1.97-4.52) and grade B patients (HR: 1.92; 95% CI: 1.29-2.86) (log-rank P < 0.0001). Echocardiographic congestion grade improved the predictive value when added to the age, sex, New York Heart Association functional class, and N-terminal pro-B-type natriuretic peptide, not only in sinus rhythm (Uno C-statistic: 0.670 vs 0.655) but in AF (Uno C-statistic: 0.667 vs 0.639).

CONCLUSIONS

Echocardiographic congestion grade has prognostic value in patients with HFpEF with and without AF.

Out-of-hospital cardiac arrest due to acute myocardial infarction possibly caused by coronary vasospasm

A 60-year-old man with out-of-hospital cardiac arrest was transported to our hospital by an emergency medical service. Ventricular fibrillation was finally terminated after the initiation of circulation support by percutaneous cardiopulmonary support device. Although acute myocardial infarction was suspected, emergency coronary angiography could not identify the culprit lesion of myocardial infarction while there were multiple intermediate stenotic lesions. Since re-elevation of troponin I was recorded on the 4^th day after admission, coronary angiography was performed again, and diffuse severe stenosis in the right coronary artery and total occlusion in the left circumflex coronary artery that disappeared by the injection of isosorbide dinitrate was detected. Therefore, we reached the diagnosis of acute myocardial infarction due to coronary vasospasm. It is very rare that emergency coronary angiogram reveals coronary vasospasm at the culprit lesion of myocardial infarction. The guideline recommends calcium channel antagonist and long-acting nitrates for vasospastic angina; however, it would be really difficult to make correct diagnosis of coronary vasospasm among the patients with acute myocardial infarction or out-of-hospital cardiac arrest. Repeated measurements of troponin and coronary angiography identified the cause of acute myocardial infarction as coronary vasospasm in the present case. <Learning objective: Coronary vasospasm may be one of important causes of acute MI and of OHCA, although it is difficult to be diagnosed correctly. We should always take into consideration the possibility of coronary vasospasm as the cause of acute MI or OHCA. Repeated measurements of troponin and coronary angiography were useful for the diagnosis of coronary vasospasm in the present case.>.

A case report of successful stent implantation through a fractured stent-strut in a superficial femoral artery based on bench testing simulation

Background

Stent implantation through the stent-strut of a previously implanted self-expandable stent in the superficial femoral artery (SFA) is not usually performed because the additional stent cannot dilate sufficiently. The key point to achieve sufficient expansion of an additional stent is to break the stent-strut of the previously implanted stent. However, there is no report of how to break the stent-strut.

Case summary

A 72-year-old man was admitted to our hospital with acute rest pain and coldness of his left leg; he was diagnosed with acute limb ischaemia. The angiogram demonstrated a fractured stent as well as stent occlusion in the left distal SFA. The guidewire could pass only through the stent-strut because of stent fracture. Fortunately, balloon angioplasty through the stent-strut and thrombolysis achieved successful revascularization. Thereafter, an additional stent was implanted in an attempt to manage the fractured and deformed stent. To obtain sufficient expansion of the additional stent, an experimental study to examine the balloon diameter and pressure to break the stent-strut was performed. Based on the results of the experiment, the stent-strut was successfully broken, and the additional stent was expanded through the stent-strut on the second intervention.

Discussion

If an additional self-expandable stent is deployed through the stent-strut directly, it would not be sufficiently dilated. The key point in such a case is to break the stent-strut of the previously implanted stent by balloon inflation before deployment of the additional stent. The experimental study examined the balloon diameter and pressure that can break the stent-strut. This information would be useful when we implant an additional stent through a stent-strut.

Clinical and Angiographic Features of Patients With Out-of-Hospital Cardiac Arrest and Acute Myocardial Infarction

BACKGROUND

Sudden cardiac arrest is a serious complication of acute myocardial infarction (MI). Although in-hospital mortality from MI has decreased, the mortality of MI patients complicated with out-of-hospital cardiac arrest (OHCA) remains high. However, the features of acute MI patients with OHCA have not been well known.

OBJECTIVES

We sought to characterize the clinical and angiographic features of acute MI patients with OHCA comparing with those without OHCA.

METHODS

We retrospectively analyzed 480 consecutive patients with acute MI undergoing percutaneous coronary intervention. Patients complicated with OHCA were compared with patients without OHCA.

RESULTS

Of the patients, 141 (29%) were complicated with OHCA. Multivariate analysis revealed that age (odds ratio [OR]: 0.8; 95% confidence interval [CI]: 0.7 to 0.9 per 5 years; p < 0.001), estimated glomerular filtration rate (OR: 0.8; 95% CI: 0.7 to 0.8 per 10 ml/min/1.73 m²; p < 0.001), peak creatine kinase-myocardial band (OR: 1.3; 95% CI: 1.2 to 1.4 per 10² U/l; p < 0.001), calcium-channel antagonists use (OR: 0.4; 95% CI: 0.2 to 0.7; p = 0.002), the culprit lesion at the left main coronary artery (OR: 5.3; 95% CI: 1.9 to 15.1; p = 0.002), and the presence of chronic total occlusion (OR: 2.9; 95% CI: 1.5 to 5.7; p = 0.001) were significantly associated with OHCA.

CONCLUSIONS

Younger age, no use of calcium-channel antagonists, worse renal function, larger infarct size, culprit lesion in the left main coronary artery, and having chronic total occlusion were associated with OHCA.

Transient increase in blood thrombogenicity may be a critical mechanism for the occurrence of acute myocardial infarction

Although the mechanism for the occurrence of acute myocardial infarction (MI) has been investigated by many pathological and clinical studies, it has not been adequately clarified yet. Although the disruption of vulnerable plaque is a well-known cause of acute MI, there are many silent plaque disruptions detected in the coronary artery by intravascular imaging studies. Therefore, many vulnerable plaques may disrupt and heal without causing acute MI. Some additional mechanisms other than the disruption of vulnerable plaque would be essential for the onset of acute MI. On the other hand, blood thrombogenicity would change dynamically due to circadian rhythms and many other factors. The combination of plaque and blood thrombogenicity would play an important and determinant role for the onset of acute MI.

Prognostic impact of nutritional status and physical capacity in elderly patients with acute decompensated heart failure

Aims

Nutritional status as well as physical capacity is related to prognosis in patients with heart failure. The purpose of this study was to explore a simple prognostic indicator in patients with acute decompensated heart failure (ADHF) by including both nutritional status and physical capacity.

Methods and results

Patients hospitalized with ADHF (N = 203; mean age, 81 years) were enrolled. We evaluated the geriatric nutritional risk index (GNRI) on hospital admission and at discharge. A GNRI score < 92 was defined as malnutrition. Physical capacity was evaluated by simple walking test to determine if patients could walk 200 m, with a Borg scale score ≤ 13, without critical changes in vital signs. Primary endpoints were mortality and heart failure rehospitalization within 2 years. A total of 49% and 48% of patients showed malnutrition on admission and at discharge, respectively. Malnutrition at discharge was more strongly related to mortality [hazard ratio (HR) 3.382, 95% confidence interval (CI) 1.900–6.020, P < 0.0001)] than that on admission (HR 2.448, 95% CI 1.442–4.157, P = 0.001) by univariable analysis. Malnutrition at discharge was related to mortality (HR 2.370, 95% CI 1.166–4.814, P = 0.02), but malnutrition on admission was not related (HR 1.538, 95% CI 0.823–2.875, P = 0.18) by multivariable analysis. Almost half of patients (45%) could not walk 200 m, which was significantly related to mortality by univariable analysis (HR 3.303, 95% CI 1.905–5.727, P < 0.0001), but was not by multivariable analysis (HR 1.990, 95% CI 0.999–3.962, P = 0.05). The combined index including both GNRI and simple walking test was an independent and stronger predictor of mortality than either index alone by multivariable analysis (HR 2.249, 95% CI 1.362–3.716, P < 0.01). Neither malnutrition nor low physical capacity was related to heart failure rehospitalization by univariable analysis (HR 0.702, 95% CI 0.483–1.020, P = 0.06; HR 1.047, 95% CI 0.724–1.515, P = 0.81, respectively). Malnutrition at discharge significantly reduced heart failure rehospitalization by multivariable analysis (HR 0.431, 95% CI 0.266–0.698, P < 0.01). When patients were classified into Group G (both nutritional status and physical capacity at discharge were good), Group E (either was good), and Group B (both were bad), mortality rates were significantly different among the groups (log rank P < 0.0001).

Conclusion

A simple indicator including both nutritional status and physical capacity may predict 2 year mortality in elderly patients with ADHF.

Relation of Chronic Total Occlusion to In-Hospital Mortality in the Patients With Sudden Cardiac Arrest Due to Acute Coronary Syndrome

Although the presence of chronic total occlusion (CTO) has been associated with long-term mortality in the patients with ST-segment elevation myocardial infarction, the influence of having CTO on in-hospital mortality in sudden cardiac arrest (SCA)-acute coronary syndrome (ACS) patients has not been reported. Therefore, we examined the association between the presence of CTO and in-hospital mortality in those patients. Consecutive 106 SCA-ACS patients who received coronary angiography were retrospectively included. The factors associated with in-hospital mortality were analyzed. Among 106 patients, 40 (38%) patients died during hospitalization. Multivariate analysis revealed presence of CTO dependent on infarct-related artery (IRA-dependent-CTO) (hazard ratio [HR] = 2.88, p = 0.004), diabetes mellitus (HR = 2.04, p = 0.044), percutaneous cardiopulmonary support use (HR = 2.22, p = 0.045), successful recanalization (HR = 0.31, p = 0.004), and peak creatine kinase muscle-brain fraction (HR = 1.11, p < 0.001) were significantly associated with mortality. In conclusion, presence of IRA-dependent-CTO was significantly associated with in-hospital mortality in SCA-ACS patients.

A novel scoring system to predict delirium and its relationship with the clinical course in patients with acute decompensated heart failure

BACKGROUND

Delirium is known to be a poor prognostic factor in patients with acute decompensated heart failure (ADHF). The purpose of this study was to determine predictors of delirium on admission of ADHF patients, and to establish a scoring formula to identify patients at high risk for delirium.

METHODS AND RESULTS

We recorded the Intensive Care Delirium Screening Checklist (ICDSC) score in 120 ADHF patients during their stay in the coronary care unit (CCU). Patients with a highest ICDSC score of 4 or more were diagnosed with delirium. We examined independent candidate predictors of delirium using multivariate logistic regression analysis and developed the following scoring formula, the delirium prediction score (DPS), using independent predictors of delirium and their regression coefficients: DPS=inferior vena cava diameter+C-reactive protein (and additionally +10 for patients with a history of cerebral infarction). Receiver operating curve analysis indicated that evaluation using this scoring system at the time of admission was able to predict delirium with high accuracy (C-statistic: 0.885). In addition, the calculated scores had significantly positive correlations with duration of CCU stay and overall length of hospital stay.

CONCLUSIONS

We established a novel scoring system to predict on admission the likelihood of development of delirium in ADHF patients; this system also predicts prolongation of intensive care and hospital stay.

Changes in left ventricular relaxation after azelnidipine treatment in hypertensive patients with diabetes: subanalysis of a prospective single-arm multicentre study

OBJECTIVES

We previously demonstrated that a calcium channel blocker, azelnidipine, improves left ventricular relaxation in patients with hypertension and diastolic dysfunction in a multicentre, Clinical impact of Azelnidipine on Left VentricuLar diastolic function and OutComes in patients with hypertension (CALVLOC) trial. The objectives of the present subanalysis were to investigate the differences in diastolic function in hypertensive patients with and without diabetes, and the efficacy of azelnidipine on diastolic function among them.

DESIGN

Subanalysis of a prospective single-arm multicentre study.

PARTICIPANTS

228 hypertensive patients with normal ejection fraction and impaired left ventricular relaxation (septal e' velocity<8 cm/s on echocardiography) enrolled for CALVLOC trial. They were divided into two groups based on presence or absence of diabetes.

INTERVENTIONS

Administration of 16 mg of azelnidipine for 8 months (range 6-10 months).

MAIN OUTCOME MEASURES

Septal e' velocity before and at the end of the study.

RESULTS

Whereas patients with diabetes (n=53, 23.2%) had lower systolic blood pressure (BP) than patients without diabetes (155±17 vs 161±16 mm Hg, p=0.03), they had lower e' velocity (5.7±1.5 vs 6.1±1.4 cm/s, p=0.04) at baseline. Azelnidipine decreased BP and heart rate, and increased e' velocity similarly in patients with diabetes (5.7±1.5 to 6.3±1.5 cm/s, p=0.0003) and without diabetes (6.1±1.4 to 6.9±1.4 cm/s, p<0.0001). Increase in e' velocity was not influenced by presence of diabetes, and patients with diabetes still had lower e' velocity after treatment (p=0.006). There was a significant correlation between increase in e' velocity and decrease in systolic BP (R=0.25, p=0.0001), which was not influenced by diabetes.

CONCLUSIONS

Comorbid diabetes could impair left ventricular relaxation independently in patients with hypertension, which might not be improved solely by BP lowering.

Cause of very late recurrence of atrial fibrillation or flutter after catheter ablation for atrial fibrillation

The major mechanism underlying the early recurrence of atrial fibrillation (AF) after ablation is mainly reconnection of the isolated pulmonary vein (PV); however, the mechanism responsible for very late recurrence (VLR) has not been fully elucidated. The purpose of the present study was to investigate the mechanism underlying VLR. The study population included 150 consecutive patients with AF who underwent a second session of catheter ablation because of recurrence. We divided them into 2 groups according to the point of initial AF recurrence: the late recurrence group (LR group, initial recurrence 3 to 12 months after ablation, n = 124) and the VLR group (initial recurrence >12 months after ablation, n = 26). We identified PVs with ectopic foci (trigger PVs) in the first procedure and checked their electrical reconnection in the second procedure. The prevalence of PV reconnection and trigger PV reconnection were significantly lower in the VLR group than in LR group (LR vs VLR, 90% vs 69% and 48% vs 27%, p = 0.007 and p = 0.045, respectively). In the VLR group, left ventricular systolic and diastolic function were significantly worse than in the LR group, and more patients in the VLR group required non-PV trigger ablation in the second session than did those in the LR group (30% vs 54%, p = 0.034). In conclusion, electrical PV reconnection contributed less to VLR than to LR. Progression of the AF substrate might be an important mechanism responsible for VLR.

Predictive factors for successful weaning from percutaneous cardiopulmonary support in patients with cardiogenic shock complicating acute myocardial infarction

BACKGROUND AND PURPOSE

Percutaneous cardiopulmonary support (PCPS) is useful in the rescue of patients who have experienced severe cardiogenic shock. We investigated the predictive factors of survival among patients with cardiogenic shock requiring PCPS.

METHODS AND SUBJECTS

We enrolled 29 patients (21 men and 8 women, 73 ± 10 years old) with circulatory collapse complicating acute myocardial infarction (AMI) requiring PCPS. Fifteen patients could be weaned from PCPS and survived for more than 1 month (group A), while the other 14 patients could not (group B). We investigated the initial PCPS settings, and performed the appropriate laboratory tests. Hemodynamic data and arterial base excess (BE) values were recorded throughout the PCPS treatment.

RESULTS

There was no difference in the laboratory test results or the left ventricular ejection fraction between the groups at the start of PCPS. PCPS flow (l/min) was significantly lower in group A than in group B at the 24th hour of PCPS (2.26 ± 0.36 and 2.54 ± 0.41, respectively). There were no differences in blood pressure between the groups. During the 24-h period prior to the end of PCPS, BE remained almost normal in group A. In group B, BE decreased continuously throughout the same period. BE values were significantly lower compared to those obtained in group A 12h prior to the end of PCPS.

CONCLUSIONS

A reduction in PCPS flow without hemodynamic collapse may allow for successful weaning from PCPS. BE may be a potent factor in determining when to terminate PCPS.

Prediction of distal embolization during percutaneous coronary intervention for unstable plaques with grayscale and integrated backscatter intravascular ultrasound

OBJECTIVES

We performed microscopic examination of the debris collected by a distal protection device and investigated the usefulness of grayscale and integrated backscatter intravascular ultrasound (IB-IVUS) for the prediction of distal embolization during percutaneous coronary intervention (PCI) in cases of unstable angina.

BACKGROUND

The prediction of distal embolization during PCI has not been studied in depth because assessment of distal embolization is difficult.

METHODS

We prospectively studied 39 consecutive patients with unstable angina who underwent PCI with a filter distal protection device. The preprocedural plaque volume at target lesions was measured with grayscale IVUS and plaque characteristics were assessed with IB-IVUS. We performed microscopic examination of the particles collected by the distal protection device.

RESULTS

There was a significant correlation between the plaque volume and the number of the collected particles >100 μm in diameter (r = 0.48, P = 0.0034). Filter no-reflow (FNR) phenomenon was found in nine patients. The plaque volume was significantly greater (355 ± 133 mm(3) vs. 199 ± 90 mm(3) , P = 0.0004), and the lipid ratio was significantly higher (29.3 ± 4.3% vs. 26.1 ± 4.3 P = 0.045) in the FNR group compared with the non-FNR group. Multivariate logistic regression analysis showed that the plaque volume was an independent predictor of FNR phenomenon.

CONCLUSIONS

Although tissue characterization of IB-IVUS may provide additional information for distal embolization, plaque volume is the only significant predictor of distal embolization during PCI.

Trigger-Based Mechanism of the Persistence of Atrial Fibrillation and Its Impact on the Efficacy of Catheter Ablation

Background—

We investigated the possibility that a frequent trigger action might play a role in the development of persistent atrial fibrillation (PeAF) and the presence of a substrate.

Methods and Results—

In 263 consecutive patients who underwent catheter ablation (CA) for PeAF, electric cardioversion was performed at the beginning of the procedure to determine the presence or absence of an immediate recurrence of AF (IRAF). We defined an IRAF as a reproducible AF recurrence within 90 s after restoration of sinus rhythm by electric cardioversion. We performed a mean±SD of 1.3±0.5 sessions of CA, including pulmonary vein isolation and ablation of the premature atrial contractions that triggered the IRAF (IRAF triggers), and observed the patients for 17 (10–27) months. An IRAF was observed in 70 patients (27%), but we could not ablate the IRAF triggers in 16 (23%) of these IRAF patients. The recurrence rate of PeAF was higher in patients with an unsuccessful IRAF trigger ablation than in those with successful IRAF trigger ablation (63% versus 11%; P <0.001). A multivariable analysis also revealed that an unsuccessful IRAF trigger ablation was 1 of the independent predictors of recurrent PeAF (odds ratio, 10.9; 95% CI, 3.4–36.7).

Conclusions—

In the PeAF patients with an IRAF, successful elimination of the IRAF triggers, in addition to pulmonary vein isolation, resulted in a successful CA. These results imply that such triggers play a major role in the AF persistence in these PeAF patients.

Effect of elevated left ventricular diastolic filling pressure on the frequency of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

We investigated the relation between left ventricular diastolic dysfunction and left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF). We performed transesophageal echocardiography to examine LAA thrombus or spontaneous echo contrast (SEC) and to measure LAA emptying flow velocity in consecutive 376 patients with AF. We estimated diastolic filling pressure as the ratio of early transmitral flow velocity (E) to mitral annular velocity (e') on transthoracic echocardiogram. E/e' ratio in 28 patients (7.4%) with LAA thrombi was higher than that in patients without thrombus (18.3 ± 9.3 vs 11.4 ± 5.9, p <0.0001). The fourth quartile of E/e' (>13.6) consisted of 19 patients with thrombi and had a higher prevalence of thrombi than the others (p <0.0001). Multivariate regression analysis selected E/e' ≥13 as an independent predictor of LAA thrombus with an odds ratio of 3.50 (1.22 to 10.61) in addition to LA dimension and ejection fraction. Increased quartile of E/e' was negatively associated with LAA flow velocity and positively with rate of SEC. In conclusion, increased diastolic filling pressure is associated with a higher rate of LAA thrombus in AF, partly through blood stasis or impaired LAA function.

Automated assessment of myocardial viability after acute myocardial infarction by global longitudinal peak strain on low-dose dobutamine stress echocardiography

BACKGROUND

Low-dose dobutamine stress echocardiography (DSE) assesses myocardial viability at the early stage of acute myocardial infarction (AMI), but its assessment is subjective and variable. Automated function image (AFI) determines global longitudinal peak strain (GLPS) based on tissue tracking technique. The ability of GLPS obtained by AFI during dobutamine stress to assess myocardial viability after AMI was investigated.

METHODS AND RESULTS

Low-dose DSE at day 3 in 23 consecutive patients with AMI was performed using Vivid 7 (GE Healthcare). Segmental longitudinal peak strain with AFI and obtained GLPS was analyzed. Wall motion score index (WMSI) by echocardiography 1 month later was determined. In 18 patients, left ventriculography was also performed at 3.2±1.5 months later to obtain left ventricular ejection fraction (LVEF) and regional wall motion (RWM, SD/chord). GLPS was improved during dobutamine infusion at 10 µg · kg(-1) · min(-1) (-12.9 ± 3.5% to -15.2 ± 3.6%, P=0.0004). GLPS during dobutamine stress showed good correlations with follow-up WMSI (R=0.47, P=0.02), with peak CK-MB (R = 0.52, P=0.01), with RWM (R = -0.48, P=0.04), and with LVEF (R = -0.54, P=0.02), whereas GLPS at baseline showed no correlations with them. Averaged segmental peak strain at baseline and during stress were correlated with follow-up WMSI (R = 0.50 and 0.43, respectively), but not with LVEF.

CONCLUSIONS

GLPS during dobutamine stress determined by AFI is a promising, objective index to assess myocardial viability on the early stage of AMI.

Comparison of two- versus three-dimensional myocardial contrast echocardiography for assessing subendocardial perfusion abnormality after percutaneous coronary intervention in patients with acute myocardial infarction

Myocardial contrast echocardiography (MCE) visualizes myocardial perfusion abnormalities after acute myocardial infarction. However, the limited view of 2-dimensional echocardiography reduces its ability to estimate perfusion abnormalities, especially in the subendocardial region. Three-dimensional echocardiography provides images of the left ventricular endocardium directly. This study was conducted to evaluate the ability of 3-dimensional MCE to assess abnormalities of subendocardial perfusion. Intracoronary 2- and 3-dimensional MCE was performed after primary percutaneous coronary intervention in 47 patients with acute myocardial infarction. Myocardial perfusion within the risk area was evaluated as good, poor, or no reflow on 2-dimensional MCE or as good, poor, or no myocardial opacification in endocardium on 3-dimensional MCE. The 2 methods showed different distributions of perfusion patterns: good, poor, and no reflow on 2-dimensional MCE in 31 (66%), 9 (19%), and 7 (15%) patients and good, poor, and no myocardial opacification in endocardium on 3-dimensional MCE in 17 (36%), 16 (34%), and 14 (20%) patients, respectively. Although only 19 patients (61%) with good reflow on 2-dimensional MCE showed myocardial perfusion grade 3 on angiography, 16 of 17 patients (94%) with good myocardial opacification in endocardium on 3-dimensional MCE showed myocardial perfusion grade 3. Although there were no significant differences in peak creatine kinase among the 3 subsets classified by 2-dimensional MCE, peak creatine kinase showed significant differences not only among the 3 groups but also among the subsets classified by 3-dimensional MCE. Classification by 3-dimensional MCE also predicted regional wall motion after 4.6 +/- 2.7 months, with significant differences between each pair of groups, whereas there was significant overlap of these values between the group with poor reflow and other 2 groups by 2-dimensional MCE. In conclusion, 3-dimensional MCE is a feasible way to assess subendocardial perfusion and predicts infarct size and functional recovery more precisely than 2-dimensional MCE.

Detection and quantification of embolic particles during percutaneous coronary intervention to stable plaque: It correlates to coronary flow dynamics and myocardial damage

OBJECTIVES

We detected embolic particles liberated from plaque during percutaneous coronary intervention (PCI) as high-intensity transient signals (HITS) with a Doppler guidewire and studied their impact on coronary flow dynamics and the myocardium in patients with stable angina pectoris.

BACKGROUND

These embolic particles during PCI may cause myocardial injury. However, this was difficult to confirm because it was impossible to detect embolic particles.

METHODS

We performed balloon angioplasty followed by stenting in 31 patients while monitoring coronary flow velocity. After PCI, we measured average peak velocity at baseline and after infusion of adenosine 5'-triphosphate to calculate coronary flow velocity reserve (CFVR) and coronary resistance index (CRI). In patients with PCI to the left coronary artery (n = 21), we calculated relative CFVR as the ratio of CFVR in the target vessel to that in the reference vessel. We measured cardiac troponin T (cTnT) the day after PCI.

RESULTS

HITS were detected in 27 (87%) of 31 patients and the majority were observed after stenting. The total number of HITS was correlated with CRI (r = 0.36, P = 0.049) or relative CFVR (r = 0.65, P = 0.0036) but not with CFVR (r = 0.048, P = 0.82). Thirteen patients showed elevated cTnT (range, 0.05-0.31 ng/ml) and the total number of HITS was greater in those with elevated cTnT than in those without elevated cTnT (24 +/- 9 vs. 10 +/- 7, P = 0.0007).

CONCLUSIONS

Embolic particles are frequently observed during PCI to stable plaque and the majority are liberated after stenting. There appears to be a quantitative relationship between amounts of HITS and coronary microvessel dysfunction and minor myocardial injury.

Young MLP deficient mice show diastolic dysfunction before the onset of dilated cardiomyopathy

Targeted deletion of cytoskeletal muscle LIM protein (MLP) in mice consistently leads to dilated cardiomyopathy (DCM) after one or more months. However, next to nothing is known at present about the mechanisms of this process. We investigated whether diastolic performance including passive mechanics and systolic behavior are altered in 2-week-old MLP knockout (MLPKO) mice, in which heart size, fractional shortening and ejection fraction are still normal. Right ventricular trabeculae were isolated from 2-week-old MLPKO and wildtype mice and placed in an apparatus that allowed force measurements and sarcomere length measurements using laser diffraction. During a twitch from the unloaded state at 1 Hz, MLPKO muscles relengthened to slack length more slowly than controls, although the corresponding force relaxation time was unchanged. Active developed stress at a diastolic sarcomere length of 2.00 microm was preserved in MLPKO trabeculae over a wide range of pacing frequencies. Force relaxation under the same conditions was consistently prolonged compared with wildtype controls, whereas time to peak and maximum rate of force generation were not significantly altered. Ca2+ content of the sarcoplasmic reticulum (SR) and the quantities of Ca2+ handling proteins were similar in both genotypes. In summary, young MLPKO mice revealed substantial alterations in passive myocardial properties and relaxation time, but not in most systolic characteristics. These results indicate that the progression to heart failure in the MLPKO model may be driven by diastolic myocardial dysfunction and abnormal passive properties rather than systolic dysfunction.

Marshall vein as arrhythmogenic source in patients with atrial fibrillation: correlation between its anatomy and electrophysiological findings

BACKGROUND

Atrial fibrillation (AF) may originate from catecholamine-sensitive vein of Marshall (VOM) or its ligament in addition to pulmonary veins (PVs). The anatomy of VOM and its relation to arrhythmogenic foci in the left atrium are unknown. We studied the anatomy of VOM and its relation to foci in patients with AF.

METHODS

The study population consisted of 100 patients with AF (mean age, 62 years; chronic AF, n = 15). AF sources were determined at baseline and after isoproterenol administration without sedation. VOM was identified by balloon-occluded coronary sinus (CS) angiography. We determined its anatomy in relation to left PVs.

RESULTS

VOM was visualized in 73 patients (73%). Ninety-seven patients had 269 arrhythmogenic foci (PV, n = 77; non-PV, n = 48). Non-PV foci included left atrial posterior wall (24, 9%), left lateral area (12, 4.5%), roof (6, 2.2%), superior vena cava (28, 10.4%), crista terminalis (8, 3.0%), CS (10, 3.7%), and others (10, 3.7%). The incidence of PV foci in the left superior PV (LSPV) was significantly higher in patients with well-developed VOM than in those without (66% vs 42%, P < 0.05). Twenty-eight patients had 30 non-PV foci around the LSPV ostium. We successfully ablated the non-PV foci at the distal end of VOM in 11 patients. The ends of the VOM branches were good markers to search for non-PV foci. Seven of 11 (64%) patients with successful ablation of non-PV foci were free from arrhythmia, whereas only 6 of 17 (35%) were free from arrhythmia in those with residual non-PV foci.

CONCLUSIONS

To determine VOM anatomy is important to identify non-PV foci around the ends of VOM.

Comparison of orifice area by transthoracic three-dimensional Doppler echocardiography versus proximal isovelocity surface area (PISA) method for assessment of mitral regurgitation

Effective regurgitant orifice area is a useful index of the severity of mitral regurgitation (MR). The calculation of regurgitant orifice area using the proximal isovelocity surface area (PISA) method has some technical limitations. Three-dimensional reconstruction of the MR jet was performed using the Live 3D system on a Sonos 7500 to measure regurgitant orifice area directly in 109 cases of MR. Regurgitant orifice area was also measured by quantitative 2-dimensional echocardiography and by the PISA method. To analyze the shape of the regurgitant orifice, the ratio of the long axis to the short axis of the orifice (the L/S ratio) was calculated. Regurgitant orifice area on 3-dimensional echocardiography showed an almost identical correlation with that obtained by quantitative echocardiography (r = 0.91, p <0.0001, slope = 0.97) regardless of the L/S ratio. It was also significantly correlated with orifice area obtained using the PISA method (r = 0.93, p <0.0001). However, orifice area on 3-dimensional echocardiography was significantly larger than that obtained using the PISA method in the whole study group and in the 62 cases of MR with L/S ratios >1.5, whereas the correlation was almost identical in cases of MR with L/S ratios < or =1.5. Orifice area obtained using the PISA method also underestimated that obtained by quantitative echocardiography in cases of MR with L/S ratios >1.5. Three-dimensional echocardiography provided robust values independent of the eccentricity of the MR jet or of cardiac rhythm. In conclusion, the direct measurement of the regurgitant orifice area of MR with 3-dimensional Doppler echocardiography could be a promising method to overcome the limitations of the PISA method, especially in cases of MR with elliptic orifice shapes.

Usefulness of high-resolution real-time three-dimensional echocardiography to visualize the left ventricular endocardial surface in myocardial infarction

High-resolution real-time 3-dimensional echocardiography (RT3DE) allows observation of the left ventricular endocardial surface in vivo. This study was performed to characterize the endocardial surface structure and its contractile function in the myocardial infarction (MI) zone in relation to the healing stage. RT3DE was performed in 90 subjects: 10 normal subjects, 50 patients with Q-wave MI 2 weeks after onset (acute MI), and 30 patients >2 months after onset (healed MI). Recordings of the left ventricular endocardial surface allowed observation of the endocardial structure in 76 patients (84%) from the apical window. The endocardial surface of normal myocardium has rough muscle folds that shrink during systole, implying endocardial contraction. In acute MI, the endocardial surface had lost systolic contraction, but appeared as normal surface structure and showed normal acoustic intensity. The endocardial surface of healed MI showed loss of systolic contraction, disappearance of folds (smooth surface), and high acoustic intensity. The frequencies of smooth surface and highest acoustic intensity were significantly higher in healed MI than acute MI (72% vs 32%, 68% vs 37%, p <0.05, respectively). Loss of systolic endocardial contraction was a common finding of Q-wave MI irrespective of the healing stage, and we could roughly estimate the size of the MI from the spatial extent of the noncontractile zone with reasonable reproducibility (r = 0.90, p <0.001). In conclusion, RT3DE is a new modality that allows observation of the structure and contraction of the endocardial surface of the left ventricular wall. We can make rough estimation of the size of the MI and its healing stage from endocardial observation with RT3DE.

Effect of reactive hyperemia after coronary recanalization on myocardial tissue reperfusion by thrombolysis in myocardial infarction flow grade in acute myocardial infarction

Thrombolysis In Myocardial Infarction (TIMI) flow grade is widely used to evaluate myocardial tissue reperfusion in acute myocardial infarction (AMI), but the current grading system is incomplete. Therefore, we clarified the regulation of epicardial coronary flow velocity with the progression of microvascular dysfunction in AMI. We studied 36 patients with first anterior AMI. After intervention, we assessed TIMI flow grade and measured average peak velocity (APV) at baseline and after infusion of adenosine triphosphate (48 microg; baseline and hyperemic APVs, respectively) with a Doppler guidewire. We performed myocardial contrast echocardiography after 2 weeks to assess microvascular integrity (good reflow vs no reflow) and left ventriculography at admission and discharge (24 +/- 2 days) to measure regional wall motion (SD/chord). Patients were classified into 3 groups based on TIMI flow grade and microvascular integrity: TIMI grade 3 flow/good reflow (n = 16), TIMI grade 3 flow/no reflow (n = 12), and TIMI grade 2 flow (n = 8). Baseline APV was comparable in the patients with TIMI grade 3 flow but hyperemic APV was higher in patients with TIMI grade 3 flow/good reflow than in those with TIMI grade 3 flow/no reflow (hyperemic APV 59.3 +/- 25.8 vs 32.8 +/- 8.9 cm/s, p <0.01). All patients with TIMI grade 2 flow showed no reflow and the lowest values of baseline and hyperemic APVs. Regional wall motion at discharge was higher in patients with TIMI grade 3 flow/good reflow than in those with TIMI grade 3 flow/no reflow and TIMI grade 2 flow (-1.44 +/- 0.70, -2.69 +/- 0.31, and -2.88 +/- 0.48 SD/chord, respectively, p <0.01). In conclusion, compensatory reactive hyperemia preserves epicardial coronary flow velocity even in patients with microvascular damage, and with the progression of damage, this compensatory hyperemia can no longer preserve epicardial coronary flow velocity, and baseline APV is decreased in TIMI grade 2 flow.

Chronic pre-treatment of statins is associated with the reduction of the no-reflow phenomenon in the patients with reperfused acute myocardial infarction

AIMS

Early statin treatment has beneficial effects on prognosis after acute coronary syndrome. The no-reflow phenomenon determines the prognosis after acute myocardial infarction. We investigated the effects of statin treatment before admission on the development of the no-reflow after infarction.

METHODS AND RESULTS

We performed intracoronary myocardial contrast echocardiography in 293 consecutive patients with acute myocardial infarction undergoing successful primary percutaneous coronary intervention. There were no significant differences in the incidence of the no-reflow between the patients with and without hypercholesterolaemia. The 33 patients receiving chronic statin treatment before admission had lower incidence of the no-reflow than those without it (9.1 and 34.6%, P=0.003). They also showed better wall motion, smaller left ventricular dimensions, and better ejection fraction at 4.9+/-2.2 months later. Multivariable logistic regression analysis revealed that statin pre-treatment was a significant predictor of the no-reflow along with anterior wall infarction, ejection fraction on admission, and additional ST-elevation after reperfusion, whereas total cholesterol was not.

CONCLUSION

Chronic pre-treatment with statins could preserve the microvascular integrity after acute myocardial infarction independent of lipid lowering, leading to better functional recovery.

Chronic phospholamban inhibition prevents progressive cardiac dysfunction and pathological remodeling after infarction in rats

Ablation or inhibition of phospholamban (PLN) has favorable effects in several genetic murine dilated cardiomyopathies, and we showed previously that a pseudophosphorylated form of PLN mutant (S16EPLN) successfully prevented progressive heart failure in cardiomyopathic hamsters. In this study, the effects of PLN inhibition were examined in rats with heart failure after myocardial infarction (MI), a model of acquired disease. S16EPLN was delivered into failing hearts 5 weeks after MI by transcoronary gene transfer using a recombinant adeno-associated virus (rAAV) vector. In treated (MI-S16EPLN, n = 16) and control (MI-saline, n = 18) groups, infarct sizes were closely matched and the left ventricle was similarly depressed and dilated before gene transfer. At 2 and 6 months after gene transfer, MI-S16EPLN rats showed an increase in left ventricular (LV) ejection fraction and a much smaller rise in LV end-diastolic volume, compared with progressive deterioration of LV size and function in MI-saline rats. Hemodynamic measurements at 6 months showed lower LV end-diastolic pressures, with enhanced LV function (contractility and relaxation), lowered LV mass and myocyte size, and less fibrosis in MI-S16EPLN rats. Thus, PLN inhibition by in vivo rAAV gene transfer is an effective strategy for the chronic treatment of an acquired form of established heart failure.

Cardiac-specific overexpression of a high Ca2+ affinity mutant of SERCA2a attenuates in vivo pressure overload cardiac hypertrophy

In cardiomyocytes, calcium plays important roles as a signal in cardiac hypertrophy and contraction-relaxation cycling. Elevation of Ca2+ concentration in myoplasm is associated with the onset and progression of hypertrophy as well as the enhancement of contractility. The cardiac Ca2+ ATPase (SERCA2a) of the sarcoplasmic reticulum plays a dominant role in lowering cytoplasmic calcium levels during relaxation and is regulated by phospholamban (PLN). To examine whether the modulation of SERCA2a activity results in the attenuation of cardiac hypertrophy and enhancement of contractility, we generated transgenic mice (TG) overexpressing a high calcium affinity SERCA2a mutant (K397/400E), lacking a functional association with PLN. In the TG hearts, the apparent affinity of SERCA2a for Ca2+ significantly increased compared with their nontransgenic littermate controls. The TG showed increased contraction and relaxation, with increases in the amplitude of Ca2+ transient and rapid Ca2+ decay. Upon induction of pressure overload by transverse aortic constriction, the TG developed less cardiac hypertrophy than littermate controls did. The activation of Ca2+-sensitive protein kinase C by pressure overload was significantly attenuated in the TG hearts. Our findings indicate an association of SERCA2a activity with cardiac hypertrophy and thus a new therapeutic target for the prevention and treatment of cardiac hypertrophy.

Chronic suppression of heart-failure progression by a pseudophosphorylated mutant of phospholamban via in vivo cardiac rAAV gene delivery

The feasibility of gene therapy for cardiomyopathy, heart failure and other chronic cardiac muscle diseases is so far unproven. Here, we developed an in vivo recombinant adeno-associated virus (rAAV) transcoronary delivery system that allows stable, high efficiency and relatively cardiac-selective gene expression. We used rAAV to express a pseudophosphorylated mutant of human phospholamban (PLN), a key regulator of cardiac sarcoplasmic reticulum (SR) Ca(2+) cycling in BIO14.6 cardiomyopathic hamsters. The rAAV/S16EPLN treatment enhanced myocardial SR Ca(2+) uptake and suppressed progressive impairment of left ventricular (LV) systolic function and contractility for 28-30 weeks, thereby protecting cardiac myocytes from cytopathic plasma-membrane disruption. Low LV systolic pressure and deterioration in LV relaxation were also largely prevented by rAAV/S16EPLN treatment. Thus, transcoronary gene transfer of S16EPLN via rAAV vector is a potential therapy for progressive dilated cardiomyopathy and associated heart failure.

The antioxidant N-2-mercaptopropionyl glycine attenuates left ventricular hypertrophy in in vivo murine pressure-overload model

OBJECTIVES

In order to identify the role of reactive oxygen species (ROS) in cardiac hypertrophy, we examined the effect of N-2-mercaptopropionyl glycine (MPG) on cardiac hypertrophy.

BACKGROUND

Recent in vitro studies have suggested that ROS play an important role as a second messenger in cardiac hypertrophy. It was therefore thought to be of particular value to examine the relevance of studies using in vitro models for cardiac hypertrophy in an in vivo setting.

METHODS

The transverse thoracic aorta in mice was constricted, and MPG (100 mg/kg) was infused intraperitoneally twice daily. The animals were assessed seven days after the operation for hemodynamic functions, oxidative stress and antioxidative enzyme activities.

RESULTS

Banding of the transverse aorta in mice resulted in an increase in the ratio of heart weight to tibia length and the appearance of an endogenous atrial natriuretic factor messenger ribonucleic acid (mRNA) seven days postoperatively. Administration of MPG significantly attenuated the hypertrophic responses induced by pressure overload. Cardiac hypertrophy was accompanied by increases in heme oxygenase-1 mRNA expression and lipid peroxidation, which was eliminated by the treatment with MPG. Pressure overload led to increases in antioxidant enzyme activities, such as superoxide dismutase and glutathione peroxidase, but not catalase, activity.

CONCLUSIONS

Our results indicated that oxidative stress was increased in our model and that it plays an important role in the development of cardiac hypertrophy.