TAVI versus SAVR in intermediate-risk patients with severe aortic stenosis and chronic kidney disease: a matched comparison in a subcohort from the GARY registry

Background

According to American and recent European guidelines, both transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) may be used to treat severe aortic stenosis in a subgroup of patients with intermediate surgical risk, in spite of slight differences in recommended age limits (ACC/AHA: 65–80 years and ESC/EACTS: <75 years). A shared therapeutic decision is made with the patient, based on a heart team assessment. For this, individual factors should be taken into account. Concomitant chronic kidney disease (CKD) is a prognostic factor in such patients, and CKD stage ≥3a and ≥3b has been shown to be a significant independent risk factor for SAVR and TAVI, respectively.

Purpose

To compare TAVI vs. SAVR outcomes in a subgroup of patients for whom both therapies could possibly be considered according to current guidelines.

Methods

The large nation-wide German Aortic Valve Registry (GARY) includes data from patients treated with TAVI or SAVR. A subcohort of patients from GARY with intermediate surgical risk (age ≤80 years, STS-score 4–8) and moderate-to-severe chronic kidney disease (CKD stages 3a, 3b, and 4) was selected. A matched analysis of 704 patients undergoing TAVI and 374 undergoing SAVR was carried out using a propensity score method. Primary endpoint was 1-year survival. Clinical complications and specifically the need for postprocedural new-onset dialysis were secondary endpoints.

Results

TAVI and SAVR showed similar survival results at 1 year in a Kaplan-Meier analysis (HR [95% CI] for TAVI: 1.271 [0.795,2.031], p=0.316). Despite a numerically higher post-procedural short-term survival in TAVI patients and a numerically higher 1-year survival in SAVR patients, such differences did not reach statistical significance (96.4% vs. 94.2%, p=0.199, and 86.2% vs. 81.2%, p=0.316, respectively). In weighted analyses, need for permanent pacemaker, vascular complications, and moderate-to-severe valvular regurgitation were significantly more common with TAVI, whereas patients undergoing SAVR had significantly higher rates of myocardial infarction, and transient ischaemic attack, needed more transfusions for bleeding, and had a significantly longer intensive care unit stay and overall hospital stay. The need for new-onset dialysis for a limited time was more common after SAVR (p<0.0001); however, very few patients required chronic dialysis either after TAVI or after SAVR.

Conclusion

In a matched analysis of intermediate-risk patients with severe aortic stenosis and a concomitant moderate-to-severe CKD, for whom both TAVI and SAVR could possibly be considered, both approaches showed excellent and comparable results.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): The registry receives financial support in the form of unrestricted grants by medical device companies (Edwards Lifesciences, JenaValve Technology, Medtronic, Sorin, St. Jude Medical, Symetis S.A.).In addition, there is unrestricted support by funding statisticians by the DZHK (Deutsches Zentrum für Herz-Kreislaufforschung).

Impact of coaptation gap location on procedural strategy and outcomes following tricuspid transcatheter edge-to-edge repair: insights from the TriClip bRIGHT study

Background

As tricuspid transcatheter edge-to-edge repair (TEER) gains momentum, a better understanding of coaptation gap size and location becomes increasingly important to properly select patients for this therapy. The tricuspid valve is complex and patient phenotypes may be highly variable. It is currently unknown how location of the coaptation gap may impact procedural strategy and clinical outcomes.

Purpose

To characterize the coaptation gap in patients receiving tricuspid TEER and investigate the effect of coaptation gap location on procedural strategy and short-term outcomes.

Methods

bRIGHT is a prospective, multi-center, single arm post-market study evaluating the safety and effectiveness of the TriClip device in symptomatic patients with severe tricuspid regurgitation. Detailed echocardiographic coaptation gap measurements were performed on 135 subjects (from 24 sites) with available echo. Procedural and short-term outcomes were stratified by coaptation gap location.

Results

The biplane RV inflow/outflow and short-axis transgastric (SAX TG) views were available in 90% (122/135) and 56% (76/135) of subjects, respectively. From the SAX TG view, coaptation gap measured 8.2±3.4 and 5.2±2.4 mm in the central and mid regions of the anterior-septal (AS) coaptation line, and 6.5±3.0 and 3.7±2.0 mm in the central and mid regions of the septal-posterior (SP) coaptation line (Figure 1). Coaptation gap measured 4.7±2.4, 5.2±2.4 and 4.6±3.0 mm in the anterior, mid and posterior aspects of the RV inflow/outflow view. The largest coaptation gap presented in the AS region in 79% (95/120) of subjects. A comparison of baseline characteristics, procedural strategy and outcomes stratified by location of the largest coaptation gap is provided in Table 1. Annulus and right ventricle size and presence of pacemakers were similar between groups. Torrential TR at baseline was more common in the SP group. Clipping strategy was similar with the majority of implants placed in the AS region. Implant success and acute procedural success (APS) were achieved in the majority of patients in both groups, with the SP group showing higher APS rates, 96% vs 85%, respectively. At 30-day follow-up, subjects with the largest gap in the SP region experienced more TR reduction at 30-day follow-up, 2.8±1.6 vs 2.1±1.3 grade reduction, respectively. Clinical improvements were observed in both groups: KCCQ increased by more than 15 points on average and the majority of subjects in both groups were NYHA I/II at 30-day follow-up.

Conclusion

Coaptation gap size varies across the tricuspid valve and measurements at the intended clipping location should be taken into account when determining appropriateness of a given anatomy for tricuspid TEER. TriClip TEER offered high rates of implant and procedural success and improved clinical outcomes regardless of coaptation gap location. Subjects with SP coaptation gap localization are infrequent but should not be excluded from TEER therapy.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott

Coronary tortuosity in patients with acetylcholine-induced coronary microvascular spasm

Background

Angina pectoris in the absence of relevant epicardial stenoses (ANOCA) is frequently caused by coronary microvascular spasm. It has been speculated that the morphology of epicardial coronary arteries is associated with microvascular spasm. One hypothesis is that the vasoconstriction of microvessels leads to intraluminal pressure increase in the vascular segments proximal to the spasm, which may shift the balance of vessel forces toward vessel elongation resulting in coronary tortuosity.

Purpose

We assessed the relationship between epicardial coronary tortuosity and coronary spasm to elucidate a potential relationship between structural and functional coronary abnormalities.

Methods

610 patients (39% male, mean age 61 years) with stable angina yet unobstructed coronary arteries (<50% stenosis) were included in this study. All patients underwent invasive diagnostic coronary angiography followed by intracoronary acetylcholine (ACh) testing according to a standardized protocol. The ACh test was considered “positive” in the presence of (a) angina, ischemic ECG shifts during the test and ≥90% coronary diameter reduction (“epicardial spasm”) or (b) all above without epicardial spasm (“microvascular spasm”). Assessment of coronary tortuosity was performed using left and right coronary images in multiple projections in a blinded fashion. The number and angles of the coronary curves in late diastole determined the severity of coronary tortuosity previously defined by Eleid. Patients were divided into those with at least moderate tortuosity versus those with no or mild tortuosity.

Results

ACh-testing revealed epicardial spasm in 179 (29%) and microvascular spasm in 172 (28%) patients. The ACh-test was negative/inconclusive in the remaining 259 patients (43%). There were 298 patients (49%) with at least moderate coronary tortuosity. The remaining 312 patients had no or mild coronary tortuosity (51%). Patients with at least moderate tortuosity were more likely to have microvascular spasm (99 patients of 172 with microvascular spasm had at least moderate coronary tortuosity (58%) vs. 76 patients of 179 with epicardial spasm (43%) vs. 126 patients of 259 with negative/inconclusive ACh test (49%), p=0.017). Analysis of coronary tortuosity in patients with positive ACh-test showed that patients with at least moderate coronary tortuosity (n=175) had significantly more microvascular spasm (57%) than epicardial spasm (43%) (p=0.005). We also found that at least moderate coronary tortuosity was significantly more often found in patients with hypertension compared to patients without hypertension (230/438 vs. 71/172, p=0.015).

Conclusions

In this large cohort of ANOCA patients coronary tortuosity was associated with hypertension and microvascular spasm. Our results provide interesting insights into the relationship of coronary morphology and vasomotor function.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Berthold-Leibinger-Foundation, Ditzingen, Germany

Pulmonary vein isolation with high power, short duration ablation leads to shorter procedure times associated with high success rates: a Prospective Randomized Trial

Funding Acknowledgements

Type of funding sources: None.

Background

The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 85 and 90 %.

This prospective, randomized study investigated the efficacy of high power, short duration ablation in a temperature-controlled mode versus standard power settings in terms of single-procedure arrhythmia-free outcome, safety and procedural time.

Methods and results

A total number of 176 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group-A patients, PVI was performed with RF-energy with standard power settings of 30 Watts in a temperature-controlled mode.

The ablation procedure in group B was performed with RF-energy with higher power settings of 45 Watts. In both groups the ablation was performed with ablation index (AI) and following the CLOSE protocol (Biosense Webster Thermocool STSF).

A total of 88 patients were randomized into each group without significant differences in baseline characteristics.

During a mean follow-up of 12 ± 4 months after a single procedure, 79 (90%) patients of group A were free of arrhythmia recurrence versus 82 (93 %) patients in group B (p=ns).

With regard to the procedural data, the procedure time was significantly shorter in group B (115.35 ± 15.38 versus 96.45 ± 17.19; p<0.01), the flouroscopy time and dose area were also significantly lower in Group B (9.66 ± 3.86 vs 5.45 ± 2.35; 330.84 ± 150.36 vs 202.51 ± 135.23) and total ablation times were significantly shorter in group B ((Table 1). Both procedures were performed with a low number of complications, no pericardial effusion was seen in either group, in both groups two patients had a significant hematoma of the groin with the need of surgical repair.

Conclusions

RF-ablation with high power (45 Watts) in combination with ablation index and following the CLOSE protocol leads to shorter procedure times, a lower total ablation time and a good safety profile.

Characterization of coaptation gap in patients receiving tricuspid transcatheter edge-to-edge repair: initial observations from the bRIGHT TriClip study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott

Background

As tricuspid transcatheter edge-to-edge repair (TEER) gains momentum, the proper measurement of coaptation gap to determine optimal patients for this therapy becomes increasingly important. Currently, a single septo-lateral measurement from the short-axis transgastric (SAX TG) or RV inflow/outflow biplane view is commonly used as the representative coaptation gap measurement for a patient. However, this measurement is not necessarily performed at the intended location for TEER and may overestimate the coaptation gaps to be treated.

Purpose

To characterize the coaptation gap in patients receiving tricuspid TEER which may provide insights on how to best determine eligibility for edge-to-edge repair.

Methods

bRIGHT is a prospective, multi-center, single arm post-market study evaluating the safety and effectiveness of the TriClip device in symptomatic patients with severe tricuspid regurgitation. Detailed echocardiographic coaptation gap measurements were performed on the first 46 subjects with available echo data by two experienced echocardiographers.  Coaptation gap was measured at four levels in the SAX TG view (Figure 1) and also at the resulting long axis view from a orthogonal view taken from a RV inflow/outflow view obtained at the anterior, mid and posterior aspect of the tricuspid valve (Figure 2).

Results

The biplane RV inflow/outflow and SAX TG views were available in 91% (42/46) and 93% (43/46) of subjects, respectively. From the SAX TG view, coaptation gap measured 9.0 ± 3.9 and 4.9 ± 2.7 mm in the central and mid regions of the anterior-septal coaptation line, and 7.6 ± 3.4 and 4.0 ± 2.1 mm in the central and mid regions of the septal-posterior coaptation line (Figure 1). The largest coaptation gap presented between the anterior and septal leaflets in 78% (33/43) of subjects, with the gap extending across the anterior-septal and septal-posterior coaptation lines in  98% (42/43) of subjects.  Coaptation gap measured 6.2 ± 2.8, 6.6 ± 2.8 and 6.0 ± 3.5 mm in the anterior, mid and posterior aspects of the RV inflow/outflow view (Figure 2). In subjects with both views available, the SAX TG view resulted in larger coaptation gap measurements (+3.4 ± 3.0 mm) in 95% (38/40) of subjects. A significant, positive correlation was observed between the maximum biplane and transgastric measurements (rho = 0.648, p < 0.0001).

Conclusion

A single septo-lateral measurement may overestimate the actual gap size and potentially exclude patients who are viable candidates for TEER. Measurements in both the SAX TG and RV inflow/outflow biplane should be taken into account when determining appropriateness of a given anatomy for tricuspid TEER Future work in larger cohorts is needed to determine which coaptation gap measurements are predictive of procedural outcomes and how these measurements may influence treatment strategy. Abstract Figure 1  Abstract Figure 2

Real-world outcomes for tricuspid edge-to-edge repair: initial echocardiographic results from the TriClip bRIGHT study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott

Background

Tricuspid regurgitation (TR) is a frequent disease with a graded increase in mortality as disease severity increases. The TriClip tricuspid valve repair system (TVRS) recently gained CE mark approval in March 2020 as a transcatheter treatment option for severe TR. The bRIGHT study was initiated to evaluate real-world safety and efficacy in patients treated with the TriClip TVRS and gather data to better understand these patients and this disease.

Purpose

To report real-world, core lab adjudicated changes in TR severity and echocardiographic parameters from baseline through 30-day follow-up in subjects treated with tricuspid transcatheter edge-to-edge repair (TEER).

Methods

bRIGHT is a prospective, multi-center, single arm post-market study evaluating the safety and effectiveness of the TriClip device in symptomatic patients with severe TR.  Detailed echocardiographic assessment was performed on all available echo data for the first 175 enrolled subjects by an independent echo core lab. TR was categorized using a 5-grade scale, with the traditional "severe" grade further characterized as severe, massive and torrential.

Results

At baseline, TR was "severe" in 98% (143/146) of subjects, which further stratifies to severe in 9% (13/146), massive in 63% (92/146) and torrential in 26% (38/146) of subjects using the 5-grade scale. At 30 days, TR was reduced by ≥1 grade in 81% of subjects, with 70% of subjects at moderate or less residual TR compared to only 1% at baseline (p < 0.0001, Figure 1). Vena contracta width decreased from 0.79 ± 0.56 mm at baseline to 0.41 ± 0.37 mm at 30 days. Effective regurgitant orifice (EROA) area decreased from 0.87 ± 0.57 cm2 at baseline to 0.38 ± 0.25 cm2 at 30-days. Similarly, regurgitant volume, PISA radius and jet area showed significant reductions (Table 1). RV end diastolic dimension decreased from 4.70 ± 0.85 cm at baseline to 4.22 ± 0.83 cm at 30 days. No changes were observed in right atrial volume or right ventricular function. Subjects were treated with 1.9 ± 0.7 clips on average, with less than a 1 mmHg increase in mean tricuspid valve gradient; average gradient was 1.12 ± 0.65, 1.92 ± 1.15 and 1.97 ± 1.81mm Hg at baseline, discharge and 30 days respectively.  Tricuspid annular diameter was significantly higher in subjects with torrential TR at baseline compared to subjects with severe or massive TR (p < 0.001).

Conclusions

Tricuspid TEER with the TriClip device showed significant reduction in TR severity in a real-world setting. Significant reduction were seen in vena contracta width, PISA radius, EROA, regurgitant volume and jet area among others. The majority of patients had massive TR at baseline. Future studies in larger cohorts are needed to investigate the relationship between the extent of TR reduction and clinical outcomes. Abstract Figure 1  Abstract Table 1

Long-term follow-up of patients with MINOCA (myocardial infarction with unobstructed coronary arteries) undergoing intracoronary spasm provocation testing

Background

Up to 30% of patients presenting with acute coronary syndrome undergoing coronary angiography are found to have no culprit lesion. Among them, epicardial or microvascular spasm can be diagnosed in ∼50% of patients undergoing provocative testing. While prognostic data in patients with coronary spasm and stable angina are abundant, the outcome of patients with myocardial infarction and unobstructed coronaries (MINOCA) and coronary spasm is not clear.

Purpose

The aim of this study was to investigate the prognosis of a cohort of patients presenting with MINOCA undergoing intracoronary acetylcholine (ACH) spasm testing.

Methods

We evaluated consecutive patients with MINOCA undergoing acetylcholine testing to detect epicardial or microvascular spasm from 2014 to 2017. Other aetiologies for MINOCA such as myocarditis, supraventricular tachycardia, pulmonary embolism etc. were excluded. Data regarding mortality (cardiac/non-cardiac), nonfatal myocardial infarction (MI), repeated coronary angiography and percutaneous coronary intervention (PCI) were recorded.

Results

Of 112 patients in our study, follow-up data were available for 96 patients (86%, 51% women, mean age 63±13 years). Acetylcholine testing was positive in 51 (53%) patients. Among patients with a positive test, epicardial spasm was detected in 26 (51%) and microvascular spasm in 25 (49%) patients. After a median follow-up of 5±3.5 years, 7 deaths (7%) and 20 nonfatal myocardial infarctions (21%) occurred. Moreover, 19 patients (20%) underwent coronary angiography and 9 patients (9%) received a PCI. Comparisons of the Kaplan–Meier curves by log-rank test showed that patients with positive acetylcholine test had a worse outcome compared to those with a negative test in terms of death from any cause (p=0.01), myocardial infarction (p=0.03) and repeated coronary angiography (p=0.05).

Conclusion

This follow-up study shows that prognosis of MINOCA patients with coronary spasm on provocative testing is worse compared to patients with an uneventful test. The results underline the potential prognostic value of spasm testing in MINOCA patients.

Funding Acknowledgement

Type of funding sources: None.

Refined prediction and validation of individual risk using machine learning in transcatheter aortic valve implantation: TAVI Risk Machine (TRIM) scores

Background

Given the recent option for treatment using TAVI irrespective of surgical risk, general surgical risk scores have become less relevant, while TAVI-specific scores require refinement. Additionally, post-TAVI risk models are lacking; however, such risk models can support decision between post-TAVI treatment approaches, such as early discharge or close surveillance.

Purpose

This study aimed to predict 30-day mortality following transcatheter aortic valve implantation (TAVI) based on machine learning (ML) using data from the German Aortic Valve Registry.

Methods

Mortality risk was determined using a random forest ML model that was condensed in the newly developed TAVI Risk Machine (TRIM) scores, designed to represent clinically meaningful risk modelling before (TRIMpre) and after (TRIMpost) TAVI. Algorithm was trained and cross-validated on data of 24,452 patients and generalisation was examined on data of 5,889 patients.

Results

TRIMpost demonstrated significantly better performance than traditional scores (C-statistics value, 0.79; 95% confidence interval [CI] [0.74; 0.83]). An abridged TRIMpost score comprising 25 features (calculated using a web interface) exhibited significantly higher performance than traditional scores (C-statistics value, 0.74; 95% CI [0.70; 0.78]).

Conclusion

TRIM scores have high performance for risk estimation before and after TAVI. Together with clinical judgement, they may support standardised and objective decision-making before and after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Long-term risk of sudden cardiac death in hypertrophic cardiomyopathy - a cardiac magnetic resonance outcome study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Robert Bosch Stiftung; Deutsche Forschungsgemeinschaft

Background

Sudden cardiac death (SCD) is an appalling complication of hypertrophic cardiomyopathy (HCM). There is an ongoing discussion about the optimal SCD risk stratification strategy in HCM since established SCD risk models have suboptimal discriminative power.

Objective

To evaluate the prognostic value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for SCD risk stratification compared to the ESC SCD risk score and traditional SCD risk factors in an >10-year follow-up study.

Methods

220 consecutive patients with HCM and LGE-CMR were enrolled. Follow-up data was available in 203 patients (median age 58 years, 61% male) after a median follow-up period of 10.4 years.

Results

LGE was present in 70% of patients with a median LGE amount of 1.6%, the median ESC 5-year SCD risk score was 1.84. In the overall cohort, SCD rates were 2.3% at 5 years, 4.8% at 10 years, and 15.7% at 15 years, independent from established risk models. A LGE amount of >5% (LV mass) portends the highest risk for SCD with SCD prevalences of 5.5% at 5 years, 13.0% at 10 years and 33.3% at 15 years. Conversely, patients with no or ≤5% LGE amount (of LV mass) have favorable prognosis.

Conclusions

LGE-CMR in HCM patients allows effective 10-year SCD risk stratification beyond established risk factors. LGE amount might be added to established risk models to improve its discriminatory power. Specifically, patients with >5% amount of LGE should be carefully monitored and might be adequate candidates for primary prevention ICD during the clinical long-term course.

Abstract Figure.

Clinical outcomes after surgical or transcatheter aortic valve replacement in patients with chronic kidney disease: an analysis in 29 893 patients from the German Aortic Valve Registry

Background

Chronic kidney disease (CKD) is a key risk factor in patients undergoing transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR).

Purpose

We analyzed the impact of eGFR and different stages of chronic kidney disease (CKD), on short- and mid-term survival in patients undergoing TAVI or SAVR.

Methods

Data from 29893 patients enrolled in the German Aortic Valve registry (GARY) from January 2011 to December 2015 receiving TAVI (n=12834) or SAVR (n=17059) at 88 sites were included. The impact of renal impairment, as measured by eGFR and CKD stages, was investigated. The primary endpoint was 1-year cumulative all-cause mortality. A propensity score method was used to compare TAVI vs. SAVR in patients with intermediate risk and mild-to-moderate renal disease being eligible for both therapies.

Results

Higher CKD stages were significantly associated to lower in-hospital, 30-day- and 1-year survival rates. Both TAVI- and SAVR-treated patients in CKD 3a, 3b, 4, and 5 stages showed significant and gradually increasing HR values for 1-year all-cause mortality. The same trend persisted in multivariable analysis, although HR values for CKD 3a and 5 did not reach significance in TAVI patients, whereas CKD 4+5 did not reach statistical significance in SAVR. Likewise, eGFR as a continuous variable was a significant predictor for 1-year mortality, with the best cut-off points being 47.4 mL/min/1.73 m2 for TAVI and 59.8 mL/min/1.73 m2 for SAVR. Significant 8.6% and 9.0% increases in 1-year mortality were observed for every 5-mL reduction in eGFR for TAVI and SAVR, respectively. No significant differences in survival were found between TAVI and SAVR in a matched group of intermediate-risk patients potentially eligible for both therapies (HR [(95% CI] for TAVI vs SAVR 1.24 [0.76, 2.02], p=0.240).

Conclusions

CKD≥3b and CKD≥3a is an independent major risk factor for mortality in patients undergoing TAVI and SAVR, respectively. In the overall population of patients with severe aortic stenosis, an appropriate stratification based on CKD substage may contribute to a better selection of patients suitable for such therapies. TAVI and SAVR appear to achieve similar survival rates in intermediate-risk patients with moderate-to-severe renal dysfunction.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Unrestricted grants by medical device companies (Edwards Lifesciences, JenaValve Technology, Medtronic, Sorin, St. Jude Medical, Symetis S.A.). Unrestricted support by funding statisticians by the DZHK (Deutsches Zentrum für Herz-Kreislaufforschung).

Impact of left atrial diameter on outcome in patients undergoing edge-to-edge mitral valve repair: results from the German TRAnscatheter Mitral valve Interventions registry (TRAMI)

Background

Left atrium (LA) dimension is a marker of disease severity and outcome in primary and secondary mitral regurgitation. In transcatheter mitral valve repair LA enlargement might additionally impact on device handling and technical success through an altered anatomy and atrial annular dilatation.

Methods

Data from the multicenter German transcatheter mitral valve intervention registry “TRAMI” were used to analyse the association of baseline LA diameter by tertiles and efficacy, safety and long-term clinical outcome in patients undergoing edge-to-edge repair with the MitraClip.

Results

In 520 of 843 patients prospectively enrolled in TRAMI baseline LA diameter were reported (median [interquartile range] LA diameter in tertiles: 44 [40–46] mm, 51 [48–53] mm and 60 [55–66] mm). Larger LA diameters were significantly associated with secondary etiology of mitral regurgitation, lower ejection fraction, larger left ventricle, male sex and atrial fibrillation (all p<0.05). Technical success was not different across tertiles (96%, 95.4%, 98.4% respectively, p=0.43) as were major in-hospital cardiovascular and cerebral adverse events (mortality, myocardial infarction or stroke) (1.8%, 1.2% and 4.4%, p=0.11 across tertiles). However, 4-year mortality significantly increased with larger LA diameter (32.9%, 46.4% and 51.7% respectively, p<0.01), as did hospitalization in survivors (60%, 67.6% and 78.9% respectively, p<0.05). The association between LA diameter and all-cause mortality remained significant after multivariable adjustment including baseline left ventricular end-diastolic diameter.

Conclusion

LA enlargement is a strong and independent predictor of adverse long-term outcome in mitral regurgitation suggesting that timely transcatheter mitral valve repair may have the potential to modify outcome.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): The TRAMI registry has been supported by proprietary means of IHF. Additional funding is provided by “Deutsche Herzstiftung” and a grant from Abbott Vascular.

Mechanisms of angina in patients with biopsy-proven viral myocarditis: insights from intracoronary acetylcholine testing

Background

Patients with myocarditis often present with angina pectoris despite unobstructed coronary arteries. The underlying pathophysiological mechanism of angina in these patients remains to be elucidated. Coronary artery spasm is a well-known cause of angina in patients with unobstructed coronary arteries. In this study, we sought to assess the frequency of coronary vasomotor disorders in patients with biopsy-proven viral myocarditis.

Methods

In total, 700 consecutive patients who underwent endomyocardial biopsy for suspected myocarditis between 2008 and 2018 were retrospectively screened. Of these patients, viral myocarditis was confirmed in 303 patients defined as histological/immunohistological evidence of myocardial inflammation and presence of viral genome confirmed by PCR. Of these patients, 34 patients had angina despite unobstructed coronary arteries and underwent intracoronary acetylcholine (ACh) provocation testing in search of coronary spasm. Epicardial spasm was defined as acetylcholine-induced reproduction of the patient's symptoms associated with ischemic ECG changes and >90% epicardial vasoconstriction. Microvascular spasm was defined as symptom reproduction and ECG changes in the absence of significant epicardial vasoconstriction.

Results

Patients were 49±16 years old, 62% were male and left ventricular ejection fraction was 54±16%. Most frequent viruses were parvovirus B19 (PVB19, 59%) and human herpes virus 6 (HHV6, 26%), 2 patients had combined PVB19/HHV6 infection and 3 patients other herpesviruses (CMV, EBV, VZV). Epicardial spasm was observed in 10 patients (29%) during ACh testing and microvascular spasm was found in 11 patients (32%). The rate of coronary spasm (epicardial and microvascular) was higher in the PVB19 subgroup compared to HHV6 (80% vs. 33%, p=0.031). In particular, there was a higher prevalence of microvascular spasm in PVB19 compared to HHV6 (45% vs. 0%, p=0.018).

Conclusion

We observed a high prevalence of microvascular and epicardial spasm in patients with biopsy-proven viral myocarditis suggesting coronary spasm as a potential underlying mechanism for angina in these patients. Microvascular spasm was most often observed in patients with PVB19-associated myocarditis.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Robert-Bosch-Stiftung; Berthold-Leibinger-Stiftung

Intracoronary acetylcholine spasm testing: differences in epicardial coronary artery response between smooth and atherosclerotic coronary arteries

Background

Coronary artery spasm is an established cause for angina pectoris. Epicardial coronary spasm may occur in patients with obstructed as well as unobstructed coronary arteries. Previous studies have suggested that epicardial plaque/atherosclerosis is a prerequisite for the development of epicardial spasm. The aim of the present study was to compare the results of intracoronary acetylcholine (ACh) testing in patients with signs and symptoms of myocardial ischemia with completely smooth versus atherosclerotic yet unobstructed epicardial arteries.

Methods

Between 2008 and 2016 a total number of 617 patients with signs and symptoms of myocardial ischemia yet unobstructed epicardial arteries (<50% epicardial stenosis) was included in the present study (mean age 61±11, 61% female). All patients underwent invasive diagnostic coronary angiography followed by intracoronary ACh testing according to a standardized protocol. The ACh-test was considered “positive” in the presence of (a) angina, ischemic ECG shifts during the test and ≥75% focal or diffuse coronary diameter reduction (“epicardial coronary artery spasm”) or (b) ischemic ST-shifts and angina in the absence of epicardial spasm (“microvascular spasm”). All angiograms were assessed regarding any visible epicardial plaque/atherosclerosis in a blinded fashion and patients were categorized into those with completely smooth versus those with atherosclerotic coronary arteries. The analysis included 179 patients (29%) with epicardial spasm and 172 patients with microvascular spasm (28%). The remaining 266 patients (43%) had an uneventful or an inconclusive ACh-test result.

Results

There were 389 patients (63%) with completely smooth epicardial arteries. The remaining 228 patients (37%) had non-obstructive epicardial plaques <50%. Patients with smooth arteries developed epicardial spasm in 24%, microvascular spasm in 32% and a negative/inconclusive test result in 44% of cases. Patients with atherosclerotic arteries developed epicardial spasm in 38%, microvascular spasm in 21% and an inconclusive/negative test result in 41% of cases. On univariate analysis the presence of epicardial atherosclerosis was associated with epicardial spasm (p=0.006) whereas this was not the case for microvascular spasm (p=0.094). Multivariate analysis revealed the presence of epicardial atherosclerosis (OR 1.921, CI 1.285–2.871, p=0.001) as well as female sex (OR 1.526, CI 1.024–2.274, p=0.038) as independent predictors for epicardial spasm.

Conclusion

In patients with signs and symptoms of myocardial ischemia yet unobstructed coronary arteries the presence of epicardial atherosclerosis is an independent predictor for the occurrence of epicardial spasm but not microvascular spasm on acetylcholine testing.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Robert-Bosch-Stiftung, Berthold-Leibinger-Stiftung

Transcatheter aortic valve implantation in nonagenarians: insights from the German Aortic Valve Registry (GARY)

OBJECTIVE

The aim of this study was to compare the outcome of nonagenarians (≥ 90 years) with that of younger (< 90 years) patients undergoing transcatheter aortic valve implantation (TAVI) in current practice.

METHODS

Data are collected from the German Aortic Valve Registry (GARY), which was designed to evaluate current practice in the invasive treatment of patients with aortic valve diseases in Germany. Data were analyzed regarding procedural outcome, 30-day, and 1-year outcomes of nonagenarians in comparison to that of younger patients.

RESULTS

Between 2011 and 2015, 2436/33,051 (7.3%) nonagenarians underwent TAVI and were included in GARY. Nonagenarians were significantly more often male (45.2% vs. 40.0%, p < 0.001), frail (38.7% vs. 34.7%, p < 0.001), and had higher EuroSCORE scores than younger patient group (23.2% vs. 17.0%). Nonagenarians were significantly less often treated via transapical access (16.3% vs. 22.3%, p < 0.001). Procedure was performed significantly less often in general anesthesia (58.2% vs. 60.7%, p = 0.02) in nonagenarians, while necessity of pacemaker implantation was significantly higher in nonagenarians (27.2% vs. 24.8%, p > 0.001). The incidence of other typical postprocedural complications such as severe bleeding events and vascular complications were comparable between groups. However, 30-day (5.2% vs. 3.9%) and 1-year (22.7% vs. 17.7%) mortality rates were significantly higher among nonagenarians and age ≥ 90 years could be identified as an isolated risk factor for mortality.

CONCLUSION

TAVI is a highly standardized procedure that can be performed safely with high procedural success even in very old patients. Although mortality is significantly higher in these patients-most probably due to the intrinsic higher risk profile of the very old patients-the results are still acceptable. To optimize outcome, especially elderly patients seem to profit from a procedure under local anesthesia or conscious sedation, to minimize the rate of postoperative delirium and the length of stay and to facilitate early mobilization.

P875Myocardial perfusion reserve assessment in patients with angina pectoris and suspected coronary spasm

Background

Patients with signs and symptoms of myocardial ischemia yet unobstructed coronary arteries represent a diagnostic and therapeutic challenge. Coronary vasomotor disorders such as coronary epicardial or microvascular spasm are frequently found among these patients. They can be diagnosed using intracoronary acetylcholine testing (ACH-test). It has been shown that patients with epicardial spasm have a worse prognosis compared to patients with microvascular spasm. The reasons for this finding are however not apparent. We speculated in this study that patients with epicardial spasm have a worse vasomotor dysfunction compared to patients with microvascular spasm or normal ACH-test. To assess this hypothesis all patients in this study not only underwent ACH-testing but in addition also adenosine stress perfusion cardiac MRI (CMR) with calculation of the myocardial perfusion reserve index (MPRI). The latter method allows for assessment of vasodilatory function compared to the vasoconstrictor assessment using acetylcholine.

Methods

Between 2012 and 2016, 129 consecutive patients (mean age 64±13 years, 46% female) with signs and symptoms of myocardial ischemia yet unobstructed coronary arteries were enrolled in this study. All patients underwent ACH-testing as well as adenosine stress perfusion CMR. According to the results of the acetylcholine test, patients were allocated to 3 groups: a) epicardial spasm (angina, ischemic ECG changes and >75% coronary diameter reduction), b) microvascular spasm (angina, ischemic ECG changes and <75% coronary diameter reduction) and c) no evidence of coronary artery spasm. CMR-derived MPRI was calculated semiquantitatively from myocardial signal intensity-over-time curves of adenosine stress and rest perfusion.

Results

Epicardial and microvascular spasm was found in 31 (24%) and 69 (53%) patients, respectively, while 29 (22%) patients had no evidence of coronary spasm on ACH-testing. Women were more likely to have microvascular spasm than men (68% vs. 36%, p<0.001). The prevalence of epicardial spasm did not significantly differ between female and male patients (18% vs. 31%, p=0.08). MPRI was similar in patients with microvascular spasm compared to patients without spasm (1.30 vs. 1.27, p=0.43). However, patients with epicardial spasm had significantly lower MPRI than patients without spasm (1.16 vs. 1.30, p<0.05) or those with microvascular spasm (1.16 vs. 1.27, p<0.05).

Conclusion

MPRI determined by stress perfusion CMR was significantly reduced in patients with epicardial spasm compared to those with microvascular spasm or normal ACH-test. This could indicate that patients with epicardial spasm have a more generalized coronary vasomotor disorder compared to other patients. This may be the reason for the worse outcome observed and could lead to more aggressive medical therapy and closer follow-up.

Acknowledgement/Funding

This work was funded by the Robert-Bosch-Stiftung, Stuttgart, Germany and the Berthold-Leibinger-Stiftung, Ditzingen, Germany.

P6004Safety assessment and results of coronary spasm provocation testing in patients with MINOCA compared to patients with stable angina and unobstructed coronary arteries

Background

Approximately 10% of patients with acute myocardial infarction do not have a culprit lesion. Such patients have been labelled as MINOCA (myocardial infarction with non-obstructive coronary arteries) and several pathophysiological etiologies have been described as potential explanations. This includes spontaneous coronary dissection, tako-tsubo-syndrome and coronary spasm. The latter can be diagnosed during invasive provocative testing. The aim of this study was to assess the frequency of coronary spasm and the safety of intracoronary provocation testing using acetylcholine in MINOCA patients compared to patients with stable angina and unobstructed coronary arteries.

Methods

Between 2007 and 2018 180 consecutive patients with either MINOCA or stable angina and unobstructed coronary arteries were enrolled. MINOCA was defined as acute onset of chest pain with either ST-segment elevation on the ECG or significant high sensitive troponin T elevation but no relevant epicardial stenosis (<50%) according to the current ESC guidelines. All patients underwent intracoronary acetylcholine provocation testing (ACH-test) in search of coronary spasm according to a standardized protocol immediately after diagnostic coronary angiography. Apart from systematic assessment of clinical, demographic and risk factor data, data regarding complications during the ACH-test were meticulously recorded.

Results

Eighty patients with MINOCA and 100 consecutive patients with stable angina were recruited (52% women, mean age 62±13 years). Overall, 59% had hypertension and 20% had diabetes. Comparison of clinical, demographic and risk factor data did not reveal any statistically significant differences except for a female preponderance in the stable patients (61% vs. 40%, p=0.007). The ACH-test revealed a coronary vasomotor disorder in 68% of cases. In 32% of cases the ACH-test was either inconclusive or negative. Epicardial spasm was found in 31% of patients with a higher prevalence among the MINOCA patients compared to the stable angina patients (41% vs. 23%, p=0.002). Microvascular spasm was found in 37% with a higher prevalence among the stable angina patients compared to the MINOCA cohort (49% vs. 23%, p=0.002). Assessment of complications during the ACH-test revealed that 13 MINOCA patients and 15 stable angina patients had minor complications such as intermittent atrioventricular block, sinusbradycardia, paroxysmal atrial fibrillation, ventricular ectopic beats or transient hypotension. Comparison of minor complications between the two groups did not reveal statistically significant differences (16% vs. 15%, p=0.839). None of the patients experienced any irreversible complications.

Conclusion

Coronary spasm is a frequent cause for MINOCA. Intracoronary spasm provocation testing using acetylcholine is feasible in such patients. The complication rate during ACH-testing in MINOCA patients is low and comparable to patients with stable angina.

Acknowledgement/Funding

Berthold-Leibinger-Foundation, Ditzingen, Germany

P2714Time-dependent myocardial necrosis in patients suffering from ST-elevation myocardial infarction without angiographic collateral flow visualized by cardiac magnetic resonance imaging

Background

Acute complete occlusion of a coronary artery results in progressive ischemia, moving from the endocardium to the epicardium (“wavefront”). Dependent on time-to-reperfusion and collateral flow, myocardial infarction (MI) will manifest, with transmural MI portending poor prognosis. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging can detect MI with high diagnostic accuracy. Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in patients with STEMI <12 hours of symptom onset.

Purpose

We sought to visualize time-dependent necrosis in a ST-segment elevation myocardial infarction (STEMI) population by LGE-CMR.

Methods

STEMI patients with: single-vessel disease, complete occlusion with Thrombolysis in Myocardial Infarction (TIMI) score 0, absence of collateral flow (Rentrop score 0) and symptom onset <12 hours were consecutively enrolled. By LGE-CMR, area at risk (AAR) and infarct size (IS), myocardial salvage index (MSI), transmurality index, and transmurality grade (0–50%, 51–75%, 76–100%) were determined.

Results

164 patients (54±11 years, 80% male) were included. Receiver-operating-characteristic (ROC)-curve (area under the curve [AUC] = 0.81) indicating transmural necrosis revealed the best diagnostic cut-off for a symptom-to-balloon time of 121 minutes, i.e. patients with >121 minutes demonstrated increased IS, transmurality index, transmurality grade (all p-values <0.01), and decreased MSI (p<0.001) vs. patients with symptom-to-balloon times ≤121 minutes.

Conclusions

In myocardial infarction with no residual antegrade, and no collateral flow, immediate reperfusion is vital. A symptom-to-balloon time of >121 minutes causes a high grade of transmural necrosis. In the present, pure STEMI population, time to reperfusion to salvage myocardium was less than suggested by current guidelines.

2424Long-term outcome of patients with biopsy-proven viral myocarditis: 12-year results from a late gadolinium enhancement cardiac magnetic resonance study

Purpose

Myocarditis is a common cardiac disease that is associated with significant mortality as demonstrated by several studies. Late gadolinium enhancement (LGE) by cardiac magnetic resonance imaging (CMR) is a valuable tool for risk stratification of patients with suspected myocarditis. Previous studies using CMR-LGE have reported a good negative predictive value over follow-up periods of 4–6 years, while its positive predictive value was only modest. However, there is a lack of data regarding the long-term prognosis (>10 years) of these patients. This study reports an extended long-term follow-up of a large cohort of patients with biopsy-proven viral myocarditis.

Methods

At initial presentation, all patients underwent endomyocardial biopsy and CMR for the work-up of suspected myocarditis or unclear cardiomyopathy and had evidence of virus in PCR analyses. The primary endpoints were: all-cause death, cardiac death, and the occurrence of sudden cardiac death (SCD).

Results

183 patients with biopsy-proven viral myocarditis were followed for a median of 11.5 years. At baseline, patients were 52 years old, 31% were females, and the median ejection fraction was moderately reduced (44%). Initial CMR assessment revealed LGE in 101 (55%) patients, while 82 (45%) patients had LGE-negative CMR. During the follow-up period, the following endpoints occurred in the overall cohort: all-cause death (n=71, 39%), cardiac death (n=50, 27%) and SCD (n=20, 11%). Most importantly, only a single LGE-negative patient experienced a SCD during this 12-year follow-up, while all other SCDs occurred in patients with LGE-positive CMR (1% vs. 19%, p<0.001). Consequently, the negative predictive value (NPV) of normal CMR-LGE regarding SCD was 98%. In addition, cardiac mortality (12% vs. 40%, p<0.001, NPV=88%) and all-cause mortality (20% vs. 54%, p<0.001, NPV=79%) were significantly lower in patients without LGE.

Conclusion

This cohort of biopsy-proven viral myocarditis demonstrates substantial mortality (39% in 11.5 years). However, absence of LGE on CMR was associated with favorable prognosis. This was applicable regarding all-cause and cardiac mortality, but most importantly with regard to SCD with a NPV of 98% over almost 12 years median follow-up.

Acknowledgement/Funding

This work was funded by the Robert-Bosch-Stiftung, Stuttgart, Germany and the Berthold-Leibinger-Stiftung, Ditzingen, Germany.

[High-risk patients with aortic valve stenosis. Interventional therapy]

Aortic valve stenosis is the most prevalent, clinically significant valvular disorder in adult patients. Surgical valve replacement is the standard therapy for patients with symptomatic and severe aortic stenosis; however, many patients are suboptimal candidates for surgery due to age and co-morbidities. The development of transcatheter aortic valve implantation (TAVI) has broadened the therapeutic options, especially in high-risk patients. The first randomized study comparing surgical valve replacement with TAVI in operable high-risk patients show similar mortality and reduction in symptoms after a 2-year follow-up. These data support the use of this technique in high-risk patients with severe aortic stenosis.

High throughput echocardiography in conscious mice: training and primary screens

PURPOSE

Genetic engineering techniques led to an exponential increase in the number of transgenic and knock-out mouse models. For many genetically modified mice, high throughput echocardiography is an essential part of a systematic screening workflow. Many researchers perform mouse echocardiography in conscious animals to avoid anesthesia-induced impairment of cardiac function. However, it has been controversially discussed whether mice need to be habituated to handling before their cardiac function can be assessed. The aim of this study was to test the influence of training on parameters assessed during conscious mouse echocardiography. In addition, we tested whether a simple and fast echocardiography protocol has sufficient sensitivity and specificity for primary screening.

MATERIALS AND METHODS

Examined parameters include fractional shortening, heart rate and respiratory rate. A total of 139 mice were examined in this study with a total of 587 echocardiograms. 103 mice were examined on five consecutive days (with examinations on day 1 - 4 regarded as training), 36 mice were only examined on day 1 and 5.

RESULTS

Fractional shortening, heart rate and respiratory rate did not show any statistically significant difference between day 1 and day 5 in both groups. The sensitivity and specificity of fractional shortening assessment for predicting a homozygote knock out genotype were 86 % and 97 %, respectively.

CONCLUSION

We conclude that conscious mouse echocardiography can be performed in untrained mice. Fractional shortening measurements may suffice for correct phenotyping in a high throughput setting.

[Disappearing borders between cardiology and cardiothoracic surgery: status quo]

Cardiology and cardiothoracic surgery are closely related so that collaboration and communication are required to offer optimal therapy for patients. During the last decades many innovations have reduced the borders between cardiology and cardiothoracic surgery. Today, cardiologists may perform coronary interventions with good results that would have previously been the domain of coronary bypass surgery. In addition new valvular interventions have been developed, such as transfemoral or transapical aortic valve implantation and endovascular mitral valve reconstruction. New developments in cardiothoracic surgery have led to less invasive procedures and many surgical procedures can now be performed with minimally invasive techniques and without a cardiopulmonary bypass. To enable optimal therapy for patients, closer collaboration between cardiologists and cardiothoracic surgeons is required setting the stage for individualized therapy in the future.

[Diminishing borders between cardiology and cardiothoracic surgery: quo vadis?]

Increasingly complex techniques in cardiovascular medicine lead to a competitive partnership between cardiology and cardiac surgery. Common challenges will arise in the fields of coronary heart disease, heart valves, heart failure and rhythm therapy. For instance, coronary revascularization in acute myocardial infarction is no longer considered to exclusively be an interventional option. In comparison, the implantation of heart valves is increasingly carried out by cardiologists using interventional techniques. The latest designs of sutureless valves try to combine the benefits of conventional and transcatheter heart valves. Heart failure is the most common reason for hospital admission and thus an important therapeutic target for cardiology and cardiac surgery. New approaches in diagnostics, heart assist devices and cellular therapy meet this challenge.

CONCLUSION

In the future only a sensitive and transparent collaboration across transsectoral borders will offer optimal therapy in cardiovascular medicine.

Therapeutic use of ultrasound targeted microbubble destruction: a review of non-cardiac applications

The development of second generation ultrasound contrast agents has extended the diagnostic scope of ultrasound imaging. Due to their physical characteristics, a therapeutic application of such microbubble based contrast agents has been promoted. Recently, several groups have demonstrated that ultrasound targeted microbubble destruction (UTMD) may deliver drugs or gene therapy vectors to organs accessible by ultrasound, thus providing a new technique for non-invasive, organ specific delivery of bioactive substances. Most applications in this field have been tested in cardiac models, but other organs can be treated as well. This article will give an overview of the background of UTMD and its non-cardiac applications.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies

OBJECTIVE

To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability.

METHODS AND RESULTS

Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05).

CONCLUSION

MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.

Real-time myocardial contrast echocardiography for the detection of stress-induced myocardial ischemia. Comparison with 99mTc-sestamibi single photon emission computed tomography

BACKGROUND

Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects.

METHODS

Real-time MCE based on continuous infusion of Optison (8-10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg x 4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (kappa=0.72) for rest- and 86% (kappa=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, kappa=0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, kappa=0.59), LCX (86%, kappa=0.64) and RCA (80%, kappa=0.68) perfusion territories.

CONCLUSIONS

These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.

Is the "candy-wrapper" effect of (32)P radioactive beta-emitting stents due to remodeling or neointimal hyperplasia? Insights from intravascular ultrasound

A recognized limitation of radioactive stents is the development of restenosis at the stent edges, known as the "candy-wrapper" effect. The mechanisms of this effect remain incompletely understood and controversial. The aim of this study is to assess the effect of endovascular irradiation on neointima formation and vascular remodeling. (32)P Palmaz-Schatz stents (1.5-4 microCi) were implanted in 11 patients with restenosis after previous percutaneous transluminal coronary angioplasty (PTCA). Intravascular ultrasound (IVUS) images of target sites and adjunct vessel segments were acquired both during intervention and after 6 months. The angiographic restenosis rate was 54%, and the MLD decreased from 2.21 +/- 0.6 mm to 1.38 +/- 0.4 mm at follow-up (P < 0.01). IVUS analysis demonstrated that late lumen loss was the result of neointimal tissue proliferation, which was nonuniformly distributed and exaggerated at both the central articulation and the distal stent edges. Negative remodeling did not contribute to restenosis. In contrast, we found a linear relationship between increase of area stenosis and a positive remodeling index (r = 0.84, P < 0.0001). Restenosis after implantation of (32)P Palmaz-Schatz stents was mainly the result of neointimal tissue proliferation which tended to be nonuniformly distributed in the stent articulation and edges. Negative remodeling or stent recoil was not observed. Cathet Cardiovasc Intervent 2001;54:41-48.

Intravascular ultrasound for evaluation of initial vessel patency and early outcome following directional coronary atherectomy

Elastic recoil and thrombus formation may potentially occur following directional coronary atherectomy (DCA) confounding the assessment of late vascular remodeling. Since intravascular ultrasound (IVUS) data on early outcome of DCA is not available, we used IVUS to investigate whether elastic recoil or thrombus formation can affect early (4 hr) outcome. Quantitative coronary angiography (QCA) and IVUS were performed in high-grade coronary lesions in 32 consecutive patients before, immediately after, and 4 hr after DCA. Late clinical follow-up was obtained after a maximum interval of 2 years. Significant acute elastic recoil was observed by both IVUS (19%+/-14%) and QCA (19%+/-12%), but there was no further recoil after 4 hr. DCA reduced plaque area by 51%+/-13%, an effect that was stable after 4 hr, indicating the absence of relevant thrombus formation. Residual area stenosis by IVUS was not related to the occurrence of late clinical events (n = 8). Mechanical recoil or thrombus formation do not hamper initial lumen gain achieved by DCA. Although QCA significantly underestimated residual plaque burden after DCA when compared to IVUS, the degree of residual area stenosis did not identify patients suffering from cardiac events on follow-up.

Influence of catheter position and equipment-related factors on the accuracy of intravascular ultrasound measurements

BACKGROUND

Intravascular ultrasound (IVUS) is frequently used as an adjunct to coronary angiography to guide revascularization procedures and, more recently, to estimate atherosclerotic plaque volumes. Although accuracy of IVUS imaging and analysis is crucial for these measurements, available data are scarce. The purpose of this in vitro study is to determine the extent to which transducer position and equipment-related factors influence measurement accuracy.

METHODS

Cross-sectional views of tubular vessel phantoms (diameter 2-14 mm) were acquired using 3.2 French catheters in coaxially centered, eccentric and oblique positions. Catheters were sequentially connected to two different ultrasound systems (A and B) to estimate equipment-related variability. In system B, two software versions were used to analyze ultrasound images. Longitudinal views of phantom segments were reconstructed to document transducer misplacement.

RESULTS

Oblique transducer positioning resulted in a non-linear overestimation of phantom areas that was independent of lumen size and also resulted in dramatic distortions of three-dimensionally reconstructed phantom geometry. Eccentric positioning did not significantly influence measurement accuracy. In coaxial positioning, differences between measured and true areas increased non-linearly from 0.36 to 4.5 mm2 in system B and in a linear fashion from -0.01 to 2.68 mm2 in system A with increasing phantom diameters. Relative differences decreased from 11.4% to 2.9% with increasing reference areas in system B (positive off-set error). When using updated software in system B, the off-set error was negative and relative error diminished from -1.34% to 0.44% with increasing phantom size.

CONCLUSION

Transducer position and equipment-related factors influence the accuracy of intravascular ultrasound, which may lead to misinterpretation of vessel size and geometry even in straight vessel segments. Transducer position may be controlled by the reconstruction of longitudinal images. Ultrasound equipment should be calibrated before using it for quantitative measurements.

Aortic pressure-diameter relationship assessed by intravascular ultrasound: experimental validation in dogs

Intravascular ultrasound (IVUS) has emerged as an important diagnostic method for evaluating vessel diameter and vessel wall motion. To evaluate the validity of IVUS in assessing changes in the pressure-diameter relationship we compared measurements of abdominal aortic diameters derived from IVUS with those simultaneously obtained at the same site using implanted sonomicrometers in five chronically instrumented conscious dogs and in seven acutely instrumented anesthetized dogs. Five hundred eighty beats were analyzed to obtain peak systolic and end-diastolic diameters and to calculate aortic compliance at different blood pressure levels induced either by an aortic pneumatic cuff or by intravenous injections of nitroglycerin or norepinephrine. IVUS agreed closely with sonomicrometer measurements at different blood pressure levels. However, IVUS slightly but significantly underestimated aortic diameters by 0.6 +/- 0.7 mm for systolic diameters (P < 0.001) and by 0.7 +/- 0.6 mm for diastolic diameters (P < 0.001) compared with the sonomicrometer measurements. We conclude that IVUS is a feasible and reliable method to measure dynamic changes in aortic dimensions and has the potential to provide ready access to assess aortic compliance in humans.

Intraluminal ultrasound imaging of the fallopian tube wall: results of standardized in vitro investigations of pig and human tubal specimens

OBJECTIVE

To investigate to what extent anatomic structures of the tubal wall can be identified reproducibly and whether altered areas can be detected and delimited by intraluminal ultrasound.

DESIGN

Standardized in vitro experiment with descriptive evaluation of findings, comparative analysis of apparative and morphologic data, and determination of interobserver variability (video documentation, blinded reviewer).

SETTING

Department of Gynecology and Obstetrics, University of Heidelberg, Germany. SPECIMEN(S): Seventy-two human and pig fallopian tubes.

INTERVENTION(S)

Catheterization with a 2.9F or 3.2F ultrasound catheter and sonographic depiction of the fallopian tube, with either simultaneous manual and sonographic wall-thickness measurement or coagulation of the tubal wall.

MAIN OUTCOME MEASURE(S)

A correlation coefficient of r = 0.76 for manual and sonographic tubal wall measurements and K = 0.88 (with 95% confidence interval of 0.74-1.0) for interobserver variability in recognizing coagulated areas.

RESULT(S)

Tubal wall anatomy and artificially altered (coagulated) areas were displayed reproducibly with intraluminal ultrasound, thus giving a characteristic, recognizable pattern of the tubal wall.

CONCLUSION(S)

These in vitro experiments provide evidence that intraluminal ultrasound may expand the current diagnostic possibilities in cases of tubal pathology, providing nonsurgical access to the tubal wall.