Cardiac CT derived 3D reconstruction discriminates for complexity and hemodynamic effect of transcatheter mitral valve repair

Background

Transcatheter mitral valve repair (TMVR) is increasingly used to treat mitral regurgitation (MR) in high risk patients. Optimal transseptal access and guiding catheter position are essential to perform adequate repair. Anatomy of the inter-atrial septum (IAS) and mitral annulus (MA) are often complex and difficult to determine from echocardiography.

Purpose

The aim of the current study was to evaluate whether pre-TMVR cardiac CT and 3D reconstruction of the IAS and MA could discriminate for complexity and hemodynamic effect of TMVR.

Methods

Patients planned for TMVR, underwent cardiac CT scan (if eligible). Post-processing software was used to segment and reconstruct the aortic root, IAS, fossa ovalis (FO) and MA, resulting in a 3D model. The following parameters were measured in each model: (1) IAS angle (°) (2) Posterior-FO angle (°) (3) FO-perpendicularity angle (°) (4) MA area (cm2). Patient specific anatomy was categorized in 4 groups as either (1) Posterior-perpendicular (PP) FO + limited IAS angle, (2) PP FO + wide IAS angle, (3) non-PP FO + limited IAS angle or (4) non-PP FO + wide IAS angle. PP FO was defined as posterior-FO angle >65° and FO-perpendicularity angle >135°. IAS angle was considered limited if <110°. Device implantation time (min) was used to assess complexity of the procedure and was compared between the different groups. MR reduction (grades), number of clips used and mitral valve (MV) gradient (mmHg) were compared for patients with MA area <14 cm2 vs. ≥14 cm2.

Results

46 patients (mean age 75 years, 41% male) were included. Anatomy was classified (1) PP FO + limited IAS angle in 13, (2) PP FO + wide IAS angle in 13, (3) Non-PP FO + limited IAS angle in 8 and (4) Non-PP FO + wide IAS angle in 12. Median device implantation time was 20 min in group 1, compared to 39 min in group 2 (p=0.02), 33 min in group 3 (p=0.03) and 29 min in group 4 (p=0.08). In patients with MA area <14 cm2, MR reduction was greater (2.22 vs. 1.68, p=0.02), number of clips used was lower (1.44 vs. 1.79, p=0.05) and MV gradient was higher, though not significant (3.15 vs. 2.58, p=0.26)

Conclusion

The current study showed that TMVR seemed less complex in patients with an optimal anatomy. In patients with limited mitral annulus area a more favorable hemodynamic effect was achieved. Cardiac CT and 3D reconstruction could therefore be of strong aid for procedural planning of TMVR.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Abbott Vascular Anatomy and device implantation timeHemodynamic effect of annulus area

Transcatheter tricuspid valve repair: early experience in the Netherlands

Background

Symptomatic tricuspid regurgitation (TR) is increasingly prevalent and impairs quality of life and survival, despite medical treatment. Transcatheter tricuspid valve repair (TTVR) has recently become available as a treatment option for patients not eligible for tricuspid valve surgery. In this study we describe the early experience with TTVR in the Netherlands.

Methods

All consecutive patients scheduled for TTVR in two tertiary hospitals were included in the current study. Patients were symptomatic and had severe functional TR. TTVR was performed either with the MitraClip (off-label use) or dedicated TriClip delivery system and device. Procedural success was defined as achievement of clip implantation, TR reduction ≥ 1 grade and no need for re-do surgical or transcatheter intervention. Clinical improvement was evaluated after 4 weeks.

Results

Twenty-one patients (median age 78 years, 33% male, 95% New York Heart Association class ≥ 3, 100% history of atrial fibrillation) underwent TTVR. Procedural success was achieved in 16 patients, of whom 15 reported symptomatic improvement (New York Heart Association class 1 or 2). There was no in-hospital mortality and no major complications occurred. Baseline glomerular filtration rate and TR coaptation gap size were associated with procedural success.

Conclusion

The current study showed that TTVR seems a promising treatment option for patients with severe functional TR deemed high risk for surgery. Successful TR reduction is most likely in patients with limited coaptation gap size and strongly determines clinical benefit. Adequate patient selection and timing of treatment seem essential for an optimal patient outcome.

Supplementary Information

The online version of this article (10.1007/s12471-021-01613-3) contains supplementary material, which is available to authorized users.

Early mobilisation after transfemoral transcatheter aortic valve implantation: results of the MobiTAVI trial

Background

Immobilisation of patients after transfemoral transcatheter aortic valve implantation (TF-TAVI) is the standard of care, mostly to prevent vascular complications. However, immobilisation may increase post-operative complications such as delirium and infections. In this trial, we determine whether it is feasible and safe to implement early ambulation after TF-TAVI.

Methods

We prospectively included TF-TAVI patients from 2016 to 2018. Patients were assessed for eligibility using our strict safety protocol and were allocated (based on the time at which the procedure ended) to the EARLY or REGULAR group.

Results

A total of 150 patients (49%) were deemed eligible for early mobilisation, of which 73 were allocated to the EARLY group and 77 to the REGULAR group. The overall population had a mean age of 80 years, 48% were male with a Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score of 3.8 ± 1.8. Time to mobilisation was 4 h 49 min ± 31 min in the EARLY group versus 20 h 7 min ± 3 h 6 min in the REGULAR group (p < 0.0001). There were no differences regarding the primary endpoint. No major vascular complications occurred and a similar incidence of minor vascular complications was seen in both groups (4/73 [5.5%] vs 6/77 [7.8%], p = 0.570). The incidence of the combined secondary endpoint was lower in the EARLY group (p = 0.034), with a numerically lower incidence for all individual outcomes (delirium, infections, pain and unplanned urinary catheter use).

Conclusion

Early mobilisation (ambulation 4–6 h post-procedure) of TF-TAVI patients is feasible and safe. Early ambulation decreases the combined incidence of delirium, infections, pain and unplanned urinary catheter use, and its adoption into contemporary TAVI practice may therefore be beneficial.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01374-5) contains supplementary material, which is available to authorized users.

Acute alterations in glucose homeostasis impact coronary microvascular function in patients presenting with ST-segment elevation myocardial infarction

Background

Microvascular dysfunction in the setting of ST-segment myocardial infarction (STEMI) is thought to be related to stress-related metabolic changes, including acute glucose intolerance. The aim of this study was to assess the relationship between admission glucose levels and microvascular function in non-diabetic STEMI patients.

Methods

92 consecutive patients with a first anterior-wall STEMI treated with primary percutaneous coronary intervention (PPCI) were enrolled. Blood glucose levels were determined immediately prior to PPCI. After successful PPCI, at 1‑week and 6‑month follow-up, Doppler flow was measured in culprit and reference coronary arteries to calculate coronary flow velocity reserve (CFVR), baseline (BMR) and hyperaemic (HMR) microvascular resistance.

Results

The median admission glucose was 8.3 (7.2–9.6) mmol/l respectively 149.4 mg/dl [129.6–172.8] and was significantly associated with peak troponin T (standardised beta coefficient [std beta] = 0.281; p = 0.043). Multivariate analysis revealed that increasing glucose levels were significantly associated with a decrease in reference vessel CFVR (std beta = −0.313; p = 0.002), dictated by an increase in rest average peak velocity (APV) (std beta = 0.216; p = 0.033), due to a decreasing BMR (std beta = −0.225; p = 0.038) in the acute setting after PPCI. These associations disappeared at follow-up. These associations were not found for the infarct-related artery.

Conclusion

Elevated admission glucose levels are associated with impaired microvascular function assessed directly after PPCI in first anterior-wall STEMI. This influence of glucose levels is an acute phenomenon and contributes to microvascular dysfunction through alterations in resting flow and baseline microvascular resistance.

The Absorb bioresorbable vascular scaffold in real-world practice: long-term follow-up of the AMC Single Centre Real World PCI Registry

BACKGROUND

Bioresorbable scaffolds have been introduced to overcome the shortcomings of drug-eluting stents. Higher rates of device thrombosis, however, have been reported up to 3 years after implantation of the Absorb bioresorbable vascular scaffold (BVS). In the current article, we therefore report long-term clinical outcomes of the AMC Absorb Registry.

METHODS AND RESULTS

In the AMC Absorb Registry, all patients who underwent a percutaneous coronary intervention with Absorb BVS implantation between 30 August 2012 and 5 August 2013 at the Amsterdam University Medical Centre-Academic Medical Centre were included. The composite endpoint of this analysis was target-vessel failure (TVF). The median follow-up of the study cohort of the AMC Absorb Registry was 1534 days. At the time of the cross-sectional data sweep the clinical status at 4 years was known in 124 of 135 patients (91.9%). At long-term follow-up, the composite endpoint of TVF had occurred in 27 patients. The 4‑year Kaplan-Meier estimate of TVF was 19.8%. At 4 years cardiac death had occurred in 4 patients (3.2%) and target-vessel myocardial infarction in 9 (6.9%) patients. Definite scaffold thrombosis occurred in 5 (3.8%) patients. We found 1 case of very late scaffold thrombosis that occurred at 911 days after device implantation in a patient who was not on dual anti-platelet therapy.

CONCLUSION

In a patient population reflecting routine clinical practice, we found that cases of TVF continued to accrue beyond 2 years after Absorb BVS implantation.

P1849Predictors of high radiation exposure in patients undergoing contemporary transfemoral transcatheter aortic valve implantation (TF-TAVI)

Background

Transfemoral transcatheter aortic valve implantation (TF-TAVI) is a minimally invasive and life-saving treatment option in patients with severe aortic valve stenosis. The number of TAVI procedures has rapidly expanded over the past decade and will continue to expand, as will the total occupational radiation exposure for the interventional cardiologist. Therefore, interventional cardiologist are at increasing risk for developing radiation induced diseases like cataract, premature vascular aging and left-sided brain tumors.

Objectives

In the current study we determined pre-procedural characteristics associated with high radiation exposure during transfemoral TAVI to raise awareness and increase the use of adequate radiation protection.

Methods

Radiation exposure (patient exposure in DAP in mGy·cm2) was collected during (TF)-TAVI procedures (July 2014- August 2018). Univariate and multiple regression analyses were performed to identify pre-procedural factors associated with high radiation exposure.

Results

A total of 654 TF-TAVI procedures were included. Patients had a median STS-score of 4% and 47% was male. The median radiation exposure was 38,016 mGy·cm2 (24,451–55,747) and the median fluoroscopy time was 16 minutes (IQR: 11–19). During the four year study period, the mean radiation exposure per TAVI procedure decreased with 30%, while the total fluoroscopy time declined with 28%.

The majority of the population underwent the TAVI procedure under local anesthesia (99%) and were implanted with the Edwards SAPIEN 3 valve (92%). Balloon predilatation was used during 88% and balloon post-dilatation was performed in only 5% of the procedures.

Patient characteristics associated with high radiation exposure included BMI >25 (OR: 6.0, 95% CI: 3.9–9.4, p<0.001), male gender (OR: 2.8, 95% CI: 1.8–4.4, p<0.001), a large pre-procedural CT-measured valve area (>450 mm2) (OR: 1.8, 95% CI: 1.1–2.8, p=0.01), presence of a pacemaker or ICD (OR: 2.0, 95% CI: 1.0–3.9, p=0.04) and a history of atrial fibrillation (OR: 1.5, 95% CI: 1.0–2.3, p=0.04). Moreover, the performance of predilatation (OR: 2.7, 95% CI: 1.5–4.8, p=0.001) and valve-in-valve procedures (OR: 3.3, 95% CI: 1.1–10.2, p=0.04) was associated to high radiation exposure.

Predictors of radiation exposure

Conclusions

The performance of transfemoral TAVI in patients with a large stature (male, BMI >25, valve area >450 mm2), in certain groups of fragile patients (presence of pacemaker or ICD, atrial fibrillation), and performing relatively complex procedures (predilatation and valve-in-valve) was associated with high radiation exposure. These patient characteristics and procedural strategies are known before the patient enters the catheterization laboratory. Hence, in the current era of a rapidly expanding number of TAVI procedures, operators should minimize their own health risk in these high-radiation-exposure-risk TAVI procedures.

Acknowledgement/Funding

None

Can stress echocardiography identify patients who will benefit from percutaneous mitral valve repair?

The aim of the current study was to investigate whether stress echocardiography improves selection of patients who might have clinical benefit from percutaneous mitral valve repair with the MitraClip. In total, 39 patients selected for MitraClip implantation underwent preprocedural low-dose stress (dobutamine or handgrip) echocardiography from which stroke volume, ejection fraction and MR grade were measured. Outcome after MitraClip implantation was determined by New York Heart Association classification and Quality of Life questionnaires. Clinical benefit from MitraClip treatment was defined as survival and NYHA class I–II at 6 months follow-up. In total, 36 patients with a technically successful procedure were included in the analysis (mean age 79 ± 8 years, 47% male, 50% functional MR). Clinical benefit was achieved in 18 patients. All seven patients with MR decreasing during stress remained in NYHA III–IV or died within 6 months, while 62% (18 out of 29) of the patients with stable or increased MR during stress had clinical benefit (p = 0.008). Significant increase in Quality of Life on 4/8 subscales of the RAND Short Form-36 questionnaire was observed: Physical Functioning (p < 0.001), Social Functioning (p < 0.001), Mental Health (p = 0.022) and Vitality (p = 0.026) was seen in patients with an increase in stroke volume during stress echocardiography. Patients with a decreased MR during preprocedural stress echocardiography remained more symptomatic than patients with a stable or increased MR during stress. Stress echocardiography may support patient selection for percutaneous mitral valve repair.

Transcatheter aortic valve replacement alters ascending aortic blood flow and wall shear stress patterns: A 4D flow MRI comparison with age-matched, elderly controls

BACKGROUND

With the implementation of transcatheter aortic valve replacement (TAVR) in lower-risk patients, evaluation of blood flow characteristics and the effect of TAVR on aortic dilatation becomes of considerable interest. We employed 4D flow MRI in the ascending aorta of patients after TAVR to assess wall shear stress (WSS) and compare blood flow patterns with surgical aortic valve replacement (SAVR) and age- and gender-matched controls.

METHODS

Fourteen post-TAVR patients and ten age- and gender-matched controls underwent kt-PCA accelerated 4D flow MRI of the thoracic aorta at 3.0 Tesla. Velocity and wall shear stress was compared between the two groups. In addition, aortic flow eccentricity and displacement was assessed and compared between TAVR patients, controls and 14 SAVR patients recruited as part of an earlier study.

RESULTS

Compared to controls, abnormally elevated WSS was present in 30±10% of the ascending aortic wall in TAVR patients. Increased WSS was present along the posterior mid-ascending aorta and the anterior distal-ascending aorta in all TAVR patients. TAVR results in eccentric and displaced flow in the mid- and distal-ascending aorta, whereas blood flow displacement in SAVR patients occurs only in the distal-ascending aorta.

CONCLUSION

This study shows that TAVR results in increased blood flow velocity and WSS in the ascending aorta compared to age- and gender-matched elderly controls. This finding warrants longitudinal assessment of aortic dilatation after TAVR in the era of potential TAVR in lower-risk patients. Additionally, TAVR results in altered blood flow eccentricity and displacement in the mid- and distal-ascending aorta, whereas SAVR only results in altered blood flow eccentricity and displacement in the distal-ascending aorta.

KEY POINTS

• TAVR results in increased blood flow velocity and WSS in the ascending aorta. • Longitudinal assessment of aortic dilatation after TAVR is warranted in the era of potential TAVR in lower-risk patients. • Both TAVR and SAVR result in altered blood flow patterns in the ascending aorta when compared to age-matched controls.

Trends in patient characteristics and clinical outcome over 8 years of transcatheter aortic valve implantation

Aim

In the evolving field of transcatheter aortic valve implantations (TAVI) we aimed to gain insight into trends in patient and procedural characteristics as well as clinical outcome over an 8‑year period in a real-world TAVI population.

Methods

We performed a single-centre retrospective analysis of 1,011 consecutive patients in a prospectively acquired database. We divided the cohort into tertiles of 337 patients; first interval: January 2009–March 2013, second interval: March 2013–March 2015, third interval: March 2015–October 2016.

Results

Over time, a clear shift in patient selection was noticeable towards lower surgical risks including Society of Thoracic Surgeons predicted risk of mortality score and comorbidity. The frequency of transfemoral TAVI increased (from 66.5 to 77.4%, p = 0.0015). Device success improved (from 62.0 to 91.5%, p < 0.0001) as did the frequency of symptomatic relief (≥1 New York Heart Association class difference) (from 73.8 to 87.1%, p = 0.00025). Complication rates decreased, including in-hospital stroke (from 5.0 to 2.1%, p = 0.033) and pacemaker implantations (from 10.1 to 5.9%, p = 0.033). Thirty-day mortality decreased (from 11.0 to 2.4%, p < 0.0001); after adjustment for patient characteristics, a mortality-risk reduction of 72% was observed (adjusted hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.13–0.62). One-year mortality rates decreased (from 23.4 to 11.4%), but this was no longer significant after a landmark point was set at 30 days (mortality from 31 days until 1 year) (adjusted HR: 0.69, 95% CI: 0.41–1.16, p = 0.16).

Conclusion

A clear shift towards a lower-risk TAVI population and improved clinical outcome was observed over an 8‑year period. Survival after TAVI improved impressively, mainly as a consequence of decreased 30-day mortality.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1129-x) contains supplementary material, which is available to authorized users.

Five-year clinical follow-up of the STENTYS self-apposing stent in complex coronary anatomy: a single-centre experience with report of specific angiographic indications

Objectives

We sought to investigate angiographic indications for the use of the STENTYS technique and evaluated the long-term safety and clinical efficacy of the stent.

Background

Coronary lesions involving complex anatomy, including aneurysmatic, ectatic, or tapered vessel segments often carry a substantial risk of stent malapposition. The self-apposing stent technique may reduce the risk of stent malapposition and therefore improve clinical outcomes.

Methods

A total of 120 consecutive patients treated with the STENTYS stent were included (drug-eluting stent (DES) n = 101, bare-metal stent (BMS) n = 19). All lesions were scored for angiographic indications for the STENTYS stent, including aneurysms, ectasias, tapering, absolute diameters, bifurcation lesions, and saphenous vein grafts. Off-line quantitative coronary angiography analyses were performed pre-procedure and post-procedure. Five years follow-up was obtained including cardiac death, target vessel myocardial infarction (TV-MI), target vessel revascularisation, stent thrombosis, and the composite endpoint target vessel failure (cardiac death, TV-MI and target vessel revascularisation).

Results

Angiographic indications for STENTYS use were aneurysm (30%), ectasia (19%), tapering (27%), bifurcation lesions (8%), and saphenous vein graft lesions (16%) and absolute diameters (22%). Mean maximal diameter was 4.51 ± 0.99 mm. At 5‑year follow-up target vessel failure rates were 24.1% in the total cohort (DES 22.8% vs. BMS 33%, p = 0.26). Definite stent thrombosis rate was 3.8% at 5‑year follow-up in this cohort with complex and high-risk lesions (DES 4.5% vs. BMS 0%, p = 0.39).

Conclusions

Angiographic indications for the use of the self-apposing stent were complex lesions with atypical coronary anatomy. Our data showed reasonable stent thrombosis rates at 5‑year follow-up, considering the high-risk lesion characteristics.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1111-7) contains supplementary material, which is available to authorized users.

Mechanical circulatory support with the Impella 5.0 device for postcardiotomy cardiogenic shock: a three-center experience

AIM

Postcardiotomy cardiogenic shock (PCCS) is associated with high mortality rates, despite full conventional treatment. Although the results of treatment with surgically implantable ventricular assist devices have been encouraging, the invasiveness of this treatment limits its applicability. Several less invasive devices have been developed, including the Impella system. The objective of this study was to describe our three-center experience with the Impella 5.0 device in the setting of PCCS.

METHODS

From January 2004 through December 2010, a total of 46 patients were diagnosed with treatment-refractory PCCS and treated with the Impella 5.0 percutaneous left ventricular assist device at three european heart centers. Baseline and follow-up characteristics were collected retrospectively and entered into a dedicated database.

RESULTS

Within the study cohort of 46 patients, mean logistic and additive EuroSCORES were 24 ± 19 and 10 ± 4. The majority of patients underwent coronary artery bypass grafting (48%) or combined surgery (33%). Half of all patients had been treated with an intra-aortic balloon pump before 5.0-implantation, 1 patient had been treated with an Impella 2.5 device. All patients were on mechanical ventilation and intravenous inotropes. The Kaplan-Meier estimate of overall 30-day survival was 39.5%.

CONCLUSION

Thirty-day survival rates for patients with PCCS, refractory to aggressive conventional treatment and treated with the Impella 5.0 device, are comparable to those reported in studies evaluating surgically implantable VADs, whereas the Impella system is much less invasive. Therefore, mechanical circulatory support with the Impella 5.0 device is a suitable treatment modality for patients with severe PCCS.

Self-expanding intracoronary stents in the treatment of coronary artery disease: new developments and future directions

The first stent implanted in the human coronary circulation was a self-expandable (SE) stent and was introduced almost simultaneously with the first balloon-expandable (BE) stents in the late 1980s. Nowadays, the majority of the available stents are delivered by balloon expansion. While BE stents reach their final size at the time of implantation, the SE stent continues to enlarge days to weeks after implantation. Potential advantages of the self-expandable and self-apposing properties of nitinol stents, a super-elastic metallic alloy of nickel and titanium, could be reduction of acute and late acquired stent malapposition with a subsequently decreased risk of target vessel restenosis. Several nitinol stents have been developed and clinically evaluated and are now in use in daily clinical practice. However, it is important to further improve and optimize the SE stent design and apply newer strategies to the development of next generation SE stents. The present review will provide an overview of the development of these devices and the currently available clinical evidence of the contemporary SE stents.

Coronary microcirculatory dysfunction is associated with left ventricular dysfunction during follow-up after STEMI

BACKGROUND

Coronary microvascular resistance is increased after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI), which may be related in part to changed left ventricular (LV) dynamics. Therefore we studied the coronary microcirculation in relation to systolic and diastolic LV function after STEMI.

METHODS

The study cohort consisted of 12 consecutive patients, all treated with primary PCI for a first anterior wall STEMI. At 4 months, we assessed pressure-volume loops. Subsequently, we measured intracoronary pressure and flow velocity and calculated coronary microvascular resistance. Infarct size and LV mass were assessed using magnetic resonance imaging.

RESULTS

Patients with an impaired systolic LV function due to a larger myocardial infarction showed a higher baseline average peak flow velocity (APV) than the other patients (26 ± 7 versus 17 ± 5 cm/s, p = 0.003, respectively), and showed an impaired variable microvascular resistance index (2.1 ± 1.0 versus 4.1 ± 1.3 mmHg cm(-1)∙s(-1), p = 0.003, respectively). Impaired diastolic relaxation time was inversely correlated with hyperaemic APV (r = -0.56, p = 0.003) and positively correlated with hyperaemic microvascular resistance (r = 0.48, p = 0.01). LV dilatation was associated with a reduced variable microvascular resistance index (r = 0.78, p = 0.006).

CONCLUSION

A larger anterior myocardial infarction results in impaired LV performance associated with reduced coronary microvascular resistance variability, in particular due to higher coronary blood flow at baseline in these compromised left ventricles.

Six-month clinical outcomes of the Tryton Side Branch Stent for the treatment of bifurcation lesions

AIMS

Percutaneous coronary intervention (PCI) of a bifurcation lesion (BL) is still associated with poorer clinical outcomes when compared with PCI of a non-BL. Therefore, several dedicated coronary bifurcation stents, such as the Tryton Side Branch Stent™ (Tryton Medical, Durham, NC, USA), were developed to improve clinical outcomes. We investigated 6-month clinical outcomes after placement of a Tryton stent in 91 patients treated for 93 BLs in our centre.

METHODS AND RESULTS

All consecutive patients who have undergone PCI of a BL treated with the Tryton stent in our centre were included. Outcomes were defined as any death, cardiac death, myocardial infarction (MI), any revascularisation, ischaemia-driven target vessel revascularisation (TVR), ischaemia-driven target lesion revascularisation (TLR), stent thrombosis, and target vessel failure (TVF; composite of cardiac death, MI, and ischaemia-driven TVR). Event rates were estimated using the Kaplan-Meier method. Thirty-eight (42 %) patients with acute coronary syndrome (ACS) were included (16 % ST-segment elevation MI (STEMI)). The 6-month event rates were 5.4 % (death), 4.3 % (cardiac death), 2.2 % (MI), 4.5 % (any revascularisation), 4.5 % (TVR), 4.5 % (TLR) and 9.7 % (TVF).

CONCLUSION

In a real-world all-comers single-centre registry, the use of the Tryton Side Branch Stent was associated with acceptable procedural and promising clinical outcomes at 6 months, including ACS and STEMI patients.

Early onset of endothelial cell proliferation in coronary thrombi of patients with an acute myocardial infarction: implications for plaque healing

AIMS

Coronary thrombotic occlusion in ST-segment elevation myocardial infarction (STEMI) patients is often preceded by episodes of progressive growth of the thrombus mass. Similar to wound healing, the organization of thrombus could depend on ingrowth of microvessels in order to stabilize its structure. We investigated the patterns of neovascularization in different stages of coronary thrombus evolution.

MATERIAL AND METHODS

Thrombectomy materials obtained from STEMI patients were histologically classified according to thrombus age in three groups: fresh (< 1 day), lytic (1-5 days) or organized (> 5 days) thrombi. Forty thrombi of each group were randomly collected. Neovascularization in the thrombi was evaluated histomorphologically and with immunodouble stains to visualize various differentiation antigens of endothelial cells (ECs) and primitive cells.

RESULTS

Morphologically, ECs in the coronary thrombi manifested as: single cells, cell clusters or microvessels. CD31+/CD34+ ECs were present in 98% of all the thrombi. In addition, endothelial clusters were found in 63% of the fresh thrombi (< 1 day). CD105+, Ki67+, or C-kit+ ECs (active, proliferating cells) were observed in all the stages, but significantly more in organized thrombi (> 5 days) compared with fresh and lytic ones (< 5 days), and mainly as cell clusters (P ≤ 0.05 for all). CD133+ primitive cells were found only sporadically in 11% of all the samples.

CONCLUSION

EC proliferation is initiated very early, and gradually progresses during the organization process of thrombus after coronary plaque disruption, with only a limited contribution of primitive cells in this process.

Infarct size and left ventricular function in the PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST-segment Elevation (PREPARE) trial: ancillary cardiovascular magnetic resonance study

OBJECTIVES

The aim of the study was to evaluate whether primary percutaneous coronary intervention (PCI) with combined proximal embolic protection and thrombus aspiration results in smaller final infarct size and improved left ventricular function assessed by cardiovascular magnetic resonance (CMR) in ST-segment elevation myocardial infarction (STEMI) patients compared with primary PCI alone. Background Primary PCI with the Proxis system improves immediate microvascular flow post-procedure as measured by ST-segment resolution, which could result in better outcomes.

METHODS

The ancillary CMR study included 206 STEMI patients who were enrolled in the PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST-Elevation (PREPARE) trial. CMR imaging was assessed between 4 and 6 months after the index procedure.

RESULTS

There were no significant differences in final infarct size (6.1 g/m(2) vs 6.3 g/m(2), p = 0.78) and left ventricular ejection fraction (50% vs 50%, p = 0.46) between both groups. Also, systolic wall thickening in the infarct area (44% vs 45%, p = 0.93) or the extent of transmural segments (8.3% of segments vs 8.3% of segments, p = 0.60) showed no significant differences. The incidence of major adverse cardiac and cerebral events at 6 months was similar in the Proxis and control group (8% vs 10%, respectively, p = 0.43). Conclusions Primary PCI with combined proximal embolic protection and thrombus aspiration in STEMI patients did not result in significant differences in final infarct size or left ventricular function at follow-up CMR. In addition, there was no difference in the incidence of major adverse cardiac and cerebral events at 6 months.

TRIAL REGISTRATION

number ISRCTN71104460.

Persistent precordial "hyperacute" T-waves signify proximal left anterior descending artery occlusion

OBJECTIVE

To describe patients with a distinct electrocardiogram (ECG) pattern without ST-segment elevation in the presence of an acute occlusion of the proximal left anterior descending (LAD) artery.

DESIGN

Single-centre observational study.

PATIENTS

Patients with acute anterior wall myocardial infarction who were referred for primary percutaneous coronary intervention (PCI) between 1998 and 2008.

RESULTS

We identified patients with a static, distinct ECG pattern without ST-segment elevation and an occlusion of the proximal LAD artery during urgent coronary angiography before PCI. Of 1890 patients who underwent primary PCI of the LAD artery, we could identify 35 patients (2%) with this distinct ECG pattern. The ECG showed ST-segment depression at the J-point of at least 1 mm in precordial leads with upsloping ST-segments continuing into tall, symmetrical T-waves. Patients with this distinct ECG pattern were younger, more often male and more often had hypercholesterolaemia compared to patients with anterior myocardial infarction and ST-segment elevation.

CONCLUSIONS

In patients presenting with chest pain, ST-segment depression at the J-point with upsloping ST-segments and tall, symmetrical T-waves in the precordial leads of the 12-lead ECG signifies proximal LAD artery occlusion. It is important for cardiologists and emergency care physicians to recognise this distinct ECG pattern, so they can triage such patients for immediate reperfusion therapy.

Colocalisation of intraplaque C reactive protein, complement, oxidised low density lipoprotein, and macrophages in stable and unstable angina and acute myocardial infarction

BACKGROUND

C reactive protein (CRP), an important serum marker of atherosclerotic vascular disease, has recently been reported to be active inside human atherosclerotic plaques.

AIMS

To investigate the simultaneous presence of macrophages, CRP, membrane attack complex C5b-9 (MAC), and oxidised low density lipoprotein (oxLDL) in atherectomy specimens from patients with different coronary syndromes.

METHODS

In total, 54 patients with stable angina (SA; n = 21), unstable angina (UA; n = 15), and myocardial infarction (MI; n = 18) underwent directional coronary atherectomy for coronary lesions. Cryostat sections of atherosclerotic plaques were immunohistochemically stained with monoclonal antibodies: anti-CD68 (macrophages), anti-5G4 (CRP), aE11 (MAC), and 12E7 (oxLDL). Immunopositive areas were evaluated in relation to fibrous and neointima tissues, atheroma, and media. Quantitative analysis was performed using image cytometry with systematic random sampling (percentage immunopositive/total tissue area).

RESULTS

Macrophages, CRP, MAC, and oxLDL were simultaneously present in a higher proportion of fibrous tissue and atheroma of atherectomy specimens from patients with UA and MI compared with SA (p<0.05). Quantitative analysis showed significantly higher mean percentages of macrophages in plaques from patients with MI (44%) than UA (30%; p<0.01) and SA (20%; p<0.001). Significantly higher mean percentages of CRP were also seen in MI (25%) and UA (25%) compared with SA (12%; p<0.05).

CONCLUSIONS

The presence of CRP, complement, and oxLDL in a high proportion of plaque tissue from patients with unstable coronary artery disease implies that these surrogate markers have important proinflammatory effects inside atherosclerotic plaques. This may increase vulnerability to plaque rupture and thrombosis, with subsequent clinical sequelae.

Role of plaque inflammation in acute and recurrent coronary syndromes

Inflammation plays an important role in the initiation, development, progression and complications of atherosclerotic vascular disease. Our present knowledge of the elementary role of inflammation for the onset of plaque rupture in atherosclerotic coronary lesions primarily stems from autopsy studies. However, the introduction of directional coronary atherectomy catheters has provided a unique opportunity to directly investigate the role of inflammation in coronary syndromes. In this report we describe the role of coronary plaque inflammation, as determined by immunohistochemistry, on the presentation of coronary syndromes and on the clinical outcome following percutaneous interventions.

Inhibition of the tissue factor pathway of coagulation by recombinant nematode anticoagulant protein c2 during elective coronary stent implantation

BACKGROUND

Exposure of tissue factor (TF) to the circulation during coronary stent implantation initiates coagulation activation and may contribute to the risk of thrombotic complications. In this study, we investigated whether inhibition of TF-factor VIIa by recombinant Nematode Anti-coagulant Protein c2 (rNAPc2) is able to suppress haemostatic and inflammatory activity in patients undergoing elective intracoronary stenting.

METHODS

In a randomised, double-blind design, 102 patients received either placebo or rNAPc2 (biological half-life >50 hours) at doses of 3.5, 5.0, 7.5 and 10.0 μg/kg as a single subcutaneous administration two to six hours before angioplasty. All patients also received aspirin, clopidogrel and unfractionated heparin (activated clotting time >250 seconds during angioplasty). Serial blood samples were collected before and after the intervention.

RESULTS

At 30 hours after stenting, all rNAPc2 treatment groups but not the placebo group demonstrated a reduction from baseline of prothrombin fragment F1+2 and D-dimer plasma levels (to 23 and 12% below baseline values at the highest dose, respectively), which were significantly lower in three rNAPc2 groups compared with placebo (p≤0.03). TF plasma levels were initially reduced in all rNAPc2 groups and returned to baseline values 18 hours after stent implantation. These three markers all increased to above baseline values in the placebo group. Levels of P-selectin, antithrombin III and interleukin-8 were not or only slightly affected by the intervention or by rNAPc2, whereas a significant 2.8 to 4.1 fold increase of C-reactive protein plasma levels was found in all patient groups after the procedure.

CONCLUSION

In contrast to the inflammatory response, coagulation activation after elective coronary stent implantation, which is observed in spite of the use of multiple antithrombotic drugs, can be attenuated by inhibition of the TF-factor VIIa complex using rNAPc2. Inhibition of the TF-mediated pathway of coagulation may be an important target to prevent thrombotic complications after coronary stenting.

[The waiting time for heart interventions: trends for percutaneous coronary interventions and cardiothoracic interventions]

OBJECTIVE

(a) To describe trends in the number of heart interventions performed over time, (b) to determine the length of waiting lists for elective heart interventions in the Netherlands according to the monthly survey of the Supervisory Committee for Heart Interventions in the Netherlands [Begeleidingscommissie Hartinterventies Nederland (BHN)], (c) to compare the length of the waiting lists with existing standards, and (d) to determine the reliability of the waiting list survey.

DESIGN

Prospective.

METHOD

Data were obtained from the monthly waiting list survey of the 13 heart centres in the Netherlands (1 January 1999-30 November 2002) and from the intervention registry (1 January 1999-30 June 2001), which was complete for 10 centres. Both the survey and the maintenance of the registry are carried out by the Supervisory Committee for Heart Interventions in the Netherlands.

RESULTS

(a) The number of percutaneous coronary interventions performed in the Netherlands has increased. The number of cardiothoracic interventions remained stable. (b) The number of patients waiting for a percutaneous coronary intervention is increasing by 16% per annum. In November 2002 there were 751 patients on the waiting list. The number of patients waiting for a cardiothoracic intervention increased by 20% per annum until August 2001 and since then there has been a decrease of 21% per annum. In November 2002, 1557 patients were on the waiting list. (c) The percentage of patients treated within existing standards has fallen to 78% for percutaneous coronary interventions and to 53% for cardiothoracic interventions. (d) The length of the waiting list and the waiting times obtained in the survey concurred with the data taken from the intervention registry.

CONCLUSIONS

The length of the waiting list for heart interventions has increased and complies increasingly less with existing standards. The monthly waiting-list survey was a reliable method of determining the length of waiting lists for elective heart interventions.

The prognostic value of pre-procedural plasma C-reactive protein in patients undergoing elective coronary angioplasty

AIMS

The acute phase reactant C-reactive protein is an important prognostic risk factor in patients with both stable and unstable coronary artery disease. The potential prognostic implications of an abnormal pre-procedural C-reactive protein concentration in patients undergoing elective coronary angioplasty may be relevant for subsequent treatment.

METHODS AND RESULTS

Pre-procedural plasma levels of C-reactive protein were measured in 501 patients with stable coronary artery disease undergoing elective coronary angioplasty. The incidence of death or myocardial infarction during a 2-year follow-up was 10.6% (24/227) in patients with an increased C-reactive protein level (>3 mg. l(-1)) and 2.9% (8/274) in patients with a normal C-reactive protein level (RR 3.9, 95% CI 1.7-8.9). Survival without death, myocardial infarction, urgent revascularization or hospital admission for unstable angina was significantly lower in patients with an increased C-reactive protein vs patients with a normal C-reactive protein (log-rank 14.62, P<0.0001). Logistic regression analysis identified an increased C-reactive protein level as a strong independent predictor of event-free survival (RR 2.54, 95% CI: 1.44-4.47, P=0.001).

CONCLUSION

Pre-procedural C-reactive protein levels are increased in 45% of patients undergoing elective coronary angioplasty. An increased C-reactive protein level is a powerful independent prognostic indicator for subsequent cardiac events, suggesting that late clinical outcome is markedly influenced by pre-procedural systemic activation of inflammation.

Fractional flow reserve, absolute and relative coronary blood flow velocity reserve in relation to the results of technetium-99m sestamibi single-photon emission computed tomography in patients with two-vessel coronary artery disease

OBJECTIVES

We sought to perform a direct comparison between perfusion scintigraphic results and intracoronary-derived hemodynamic variables (fractional flow reserve [FFR]; absolute and relative coronary flow velocity reserve [CFVR and rCFVR, respectively]) in patients with two-vessel disease.

BACKGROUND

There is limited information on the diagnostic accuracy of intracoronary-derived variables (CFVR, FFR and rCFVR) in patients with multivessel disease.

METHODS

Dipyridamole technetium-99m sestamibi (MIBI) single-photon emission computed tomography (SPECT) was performed in 127 patients. The presence of reversible perfusion defects in the region of interest was determined. Within one week, angiography was performed; CFVR, rCFVR and FFR were determined in 161 coronary lesions after intracoronary administration of adenosine. The predictive value for the presence of reversible perfusion defects on MIBI SPECT of CFVR, rCFVR and FFR was evaluated by the area under the curve (AUC) of the receiver operating characteristics curves.

RESULTS

The mean percentage diameter stenosis was 57% (range 35% to 85%), as measured by quantitative coronary angiography. Using per-patient analysis, the AUCs for CFVR (0.70 +/- 0.052), rCFVR (0.72 +/- 0.051) and FFR (0.76 +/- 0.050) were not significantly different (p = NS). The percentages of agreement with the results of MIBI SPECT were 76%, 78% and 77% for CFVR, rCFVR and FFR, respectively. Per-lesion analysis, using all 161 measured lesions, yielded similar results.

CONCLUSIONS

The diagnostic accuracy of three intracoronary-derived hemodynamic variables, as compared with the results of perfusion scintigraphy, is similar in patients with two-vessel coronary artery disease. Cut-offvalues of 2.0 for CFVR, 0.65 for rCFVR and 0.75 for FFR can be used for clinical decision-making in this patient cohort. Discordant results were obtained in 23% of the cases that require prospective evaluation for appropriate patient management.

Early lumen diameter loss after percutaneous transluminal coronary angioplasty is related to coronary plaque burden: a role for viscous plaque properties in early lumen diameter loss

OBJECTIVES

We tested the hypothesis that lumen diameter loss within 1 h after percutaneous transluminal coronary angioplasty is related to plaque volume parameters.

BACKGROUND

Early lumen diameter loss after coronary balloon angioplasty may predict restenosis and may paradoxically decrease late lumen diameter loss. Viscous properties of the vessel wall, as would be determined by tissue volume and composition, may be involved in early lumen diameter loss.

METHODS

Early lumen diameter loss was measured with quantitative coronary angiography as the loss in lesion lumen diameter (significant loss 0.4 mm) occurring between 5 min and a median of 40 min after successful coronary balloon angioplasty in 68 patients. Thirty-nine patients were evaluated with intravascular ultrasound at the narrowest lumen cross-section of the dilated lesion, 29 patients formed a control group without intravascular ultrasound imaging. We tested the relation between intravascular ultrasound parameters and early lumen diameter loss.

RESULTS

Early lumen diameter loss of > or = 0.4 mm was present in eight patients (12%), decreasing lumen diameter from 2.26 +/- 0.36 mm to 1.73 +/- 0.43 mm. There was no difference in the frequency of early lumen diameter loss between the groups with or without intravascular ultrasound imaging. Univariate intravascular ultrasound determinants of early lumen diameter loss were media bounded area (p = 0.01), maximal plaque thickness (p = 0.02), eccentricity index (p = 0.03) and the presence of hard lesions (p = 0.02).

CONCLUSION

Early lumen diameter loss in the first hour after successful coronary balloon angioplasty occurs in a small proportion of patients. It is related to hard lesion type, maximal plaque thickness and eccentricity index, favoring a role for viscous plaque properties in early lumen diameter loss.

Recurrent unstable angina after directional coronary atherectomy is related to the extent of initial coronary plaque inflammation

OBJECTIVES

This study was performed to evaluate the relationship between plaque inflammation of the initial culprit lesion and the incidence of recurrent angina for one year after directional coronary atherectomy (DCA).

BACKGROUND

A positive correlation between coronary plaque inflammation and angiographic restenosis has been reported.

METHODS

A total of 110 patients underwent DCA. Cryostat sections were immunohistochemically stained with monoclonal antibodies CD68 (macrophages), CD-3 (T lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). The SMC and macrophage contents were planimetrically quantified as a percentage of the total tissue area. T lymphocytes were counted as the number of cells/mm2. The patients were followed for one year to document recurrent unstable angina pectoris (UAP) or stable angina pectoris (SAP).

RESULTS

Recurrent UAP developed in 16 patients, whereas recurrent SAP developed in 17 patients. The percent macrophage areas were larger in patients with recurrent UAP (27 +/- 12%) than in patients with recurrent SAP (8 +/- 4%; p = 0.0001) and those without recurrent angina (18 +/- 14%; p = 0.03). The number of T lymphocytes was also greater in patients with recurrent UAP (25 +/- 14 cells/mm2) than in patients with recurrent SAP (14 +/- 8 cells/mm2; p = 0.02) and those without recurrent angina (14 +/- 12 cells/mm2; p = 0.002). Multiple stepwise logistic regression analysis identified macrophage areas and T lymphocytes as independent predictors for recurrent UAP.

CONCLUSIONS

There is a positive association between the extent of initial coronary plaque inflammation and the recurrence of unstable angina during long-term follow-up after DCA. These results underline the role of ongoing smoldering plaque inflammation in the recurrence of unstable angina after coronary interventions.

Role of variability in microvascular resistance on fractional flow reserve and coronary blood flow velocity reserve in intermediate coronary lesions

BACKGROUND

Fractional flow reserve (FFR) and coronary blood flow velocity reserve (CFR) represent physiological quantities used to evaluate coronary lesion severity and to make clinical decisions. A comparison between the outcomes of both diagnostic techniques has not been performed in a large cohort of patients with intermediate coronary lesions.

METHODS AND RESULTS

FFR and CFR were assessed in 126 consecutive patients with 150 intermediate coronary lesions (between 40% and 70% diameter stenosis by visual assessment). Agreement between outcomes of FFR and CFR, categorized at cut-off values of 0.75 and 2.0, respectively, was observed in 109 coronary lesions (73%), whereas discordant outcomes were present in 41 lesions (27%). In 26 of these 41 lesions, FFR was <0.75 and CFR>or=2.0 (group A); in the remaining 15 lesions, FFR was >or=0.75 and CFR<2.0 (group B). Minimum microvascular resistance, defined as the ratio of mean distal pressure to average peak blood flow velocity during maximum hyperemia, showed a large variability (overall range, 0.65 to 4.64 mm Hg x cm(-1) x s(-1)) and was significantly higher in group B than in group A (2.42+/-0.77 versus 1.91+/-0.70 mm Hg x cm(-1) x s(-1); P:=0.034).

CONCLUSIONS

Our findings demonstrate the prominent role of microvascular resistance in modulating the relationship between FFR and CFR and emphasize the importance of combined pressure and flow velocity measurements to evaluate coronary lesion severity and microvascular involvement.

Triage of patients for short term observation after elective coronary angioplasty

OBJECTIVE

To evaluate triage of patients for short term observation after elective percutaneous transluminal coronary angioplasty (PTCA), as appropriate selection of patients for short term observation after angioplasty may facilitate early discharge.

METHODS

1015 consecutive patients scheduled for elective PTCA were prospectively included for short term observation. Patients with unstable angina Braunwald class III were excluded. There were no angiographic exclusion criteria. Patients were discharged from the interventional centre when considered stable during 4 hours of observation after PTCA. It was left to the operator's discretion whether to prolong the observation period. Procedural complications were defined as death, coronary bypass surgery, early repeat PTCA, and myocardial infarction.

OUTCOME MEASURES

The need for prolonged observation (> 4 hours) and the occurrence of complications. Predictors for prolonged observation and the occurrence of complications after the 4 hours observation were assessed by univariate and multivariate analysis.

RESULTS

Two patients died, including one of six patients who underwent emergency bypass surgery. In all, 922 patients (90.8%) were triaged to short term observation and had an uncomplicated three day follow up. Observation was prolonged in 87 patients (8.6%), and 40 patients had a complicated course. Independent predictors of procedural complications were acute closure (odds ratio (OR) 9.7; 95% confidence interval 4.4 to 21.4), side branch occlusion (OR 8.9; 3.4 to 23.7), no angiographic success (OR 5.1; 2.4 to 11.0), female sex (OR 3.1, 1.7 to 5.7), any unplanned stent (OR 2.8, 1.4 to 5.9), and ostial lesion (OR 2.2, 1.0 to 4.7).

CONCLUSIONS

A 4 hour observation period is safe after elective coronary angioplasty. As procedural variables are the strongest predictors of postprocedural complications, the immediate procedural results allow effective triage of patients for short term or prolonged observation in order to anticipate complications.

Plaque inflammation in restenotic coronary lesions of patients with stable or unstable angina

OBJECTIVES

To evaluate immunohistochemically various parameters of inflammation in coronary atherectomy specimens obtained from restenotic culprit lesions of patients presenting with either stable or unstable angina (UA).

BACKGROUND

There is no information regarding the relationship between atherosclerotic plaque inflammation and the severity of the coronary syndromes in patients with restenotic coronary lesions.

METHODS

A total of 37 patients with either stable angina or UA underwent directional coronary atherectomy for restenotic coronary lesions. Cryostat sections of atherectomy specimen were immunohistochemically stained with monoclonal antibodies CD68 (macrophages [MACs]), CD3 (T-lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). Smooth muscle cell contents and MAC contents were planimetrically quantified as the percentage immunopositive tissue area of the total tissue area. T-lymphocytes were counted at 100-X magnification throughout the entire section and expressed as number of cells per mm2.

RESULTS

Restenotic coronary lesions of patients with UA or stable angina showed no significant difference in SMC areas (31.9%+/-16.3% vs. 38.5%+/-18.8%, respectively; p = NS). However, restenotic coronary lesions of patients presenting with unstable angina contained significantly more MACs (24.4%+/-15.1% vs. 10.5%+/-5.8%, p = 0.001) and T-lymphocytes (18.8 cells/mm2+/-15.1 cells/mm2 vs. 8.6 cells/mm2+/-9.8 cells/mm2; p = 0.034) than patients with stable angina.

CONCLUSIONS

These results suggested that inflammation appears to affect plaque instability in restenotic coronary lesions resulting in unstable coronary syndromes.

Hyperemic coronary flow after optimized intravascular ultrasound-guided balloon angioplasty and stent implantation

OBJECTIVES

This study evaluated the acute physiological gain of adjunctive intravascular ultrasound (IVUS) guided balloon angioplasty and stent implantation.

BACKGROUND

Recent studies indicate safe coronary luminal enlargement and "stent-like" long-term outcomes using upsized balloons guided by IVUS.

METHODS

After angiographically guided balloon angioplasty in 20 patients with 1-vessel disease and normal left ventricular function, IVUS was performed to determine the size of the adjunctive balloon using the mean of the maximal luminal diameter and the maximal diameter of the external elastic membrane measured in the adjacent proximal and distal reference segments. Serial adenosine-induced hyperemic blood flow velocity measurements were performed using a 0.014" Doppler guide wire to determine the physiological lumen obstruction after standard balloon angioplasty, followed by IVUS-guided balloon angioplasty and stent implantation.

RESULTS

Upsized balloon angioplasty (increase balloon size: 0.98 +/- 0.26 mm; balloon:artery ratio 1.35 +/- 0.21) resulted in an additional increase of arterial dimensions: minimal lumen diameter (MLD) 2.18 +/- 0.38 mm to 2.73 +/- 0.51 mm; percent diameter stenosis (%DS) 34 +/- 13% to 19 +/- 22%; IVUS assessed minimal lumen area (MLA) 7.53 +/- 1.55 mm2 to 10.24 +/- 2.22 mm2 (all p < 0.0001). Major dissections (> or = type C) did not occur. Hyperemic blood flow velocity increased from 49.8 +/- 20.1 cm/s to 59.1 +/- 22.9 cm/s (p < 0.05) after IVUS-guided balloon angioplasty. Adjunctive stent implantation resulted in a further increase of MLD to 3.84 +/- 0.51 mm, %DS to -9 +/- 21% and MLA to 13.39 +/- 1.80 mm2 (all p < 0.0001), while hyperemic blood flow velocity remained unchanged (61.2 +/- 24.7 cm/s, p = 0.7).

CONCLUSIONS

Upsized IVUS-guided balloon angioplasty increases arterial coronary dimensions and the distal hyperemic blood flow velocity. Adjunctive stent implantation does not yield a further gain in the hyperemic blood flow velocity, indicating the absence of a functional residual lumen obstruction after IVUS-guided balloon angioplasty. This may explain a similar clinical outcome reported after those coronary interventions.

Functional assessment of coronary artery stenosis by doppler derived absolute and relative coronary blood flow velocity reserve in comparison with (99m)Tc MIBI SPECT

OBJECTIVE

To determine the relation between the relative and absolute coronary blood flow velocity reserve (CFVR) compared with the results of (99m)Tc MIBI single photon emission computed tomography (SPECT).

METHODS

In 37 patients with one vessel disease, (99m)Tc MIBI SPECT was performed before angioplasty, two to three weeks after angioplasty, and at six months' follow up. CFVR was measured distal to the stenosis (dCFVR) as well as in a reference coronary artery before angioplasty, immediately after angioplasty, and at late follow up. Relative CFVR (rCFVR) was calculated as the ratio between dCFVR and CFVR measured in the reference coronary artery. The optimal thresholds for reversible perfusion defects were calculated using receiver operating characteristic curves.

RESULTS

The agreement for the full range of coronary artery stenosis (n = 107, mean (SD) diameter stenosis 48 (28)%, range 0-98%) between dCFVR (cut off value 1.9) and rCFVR (cut off value 0.65) with (99m)Tc MIBI SPECT was 81% and 85%, respectively. In intermediate lesions (n = 49, diameter stenosis range 30-75%) the agreement between dCFVR (cut off value 2.0) and (99m)Tc MIBI SPECT was 72%, which increased to 78% using the rCFVR (cut off value 0.65). There was a strong linear relation between dCFVR and rCFVR (r = 0.93, p < 0.0001).

CONCLUSIONS

A best cut off value for dCFVR of 1.9 corresponds with a best cut off value of 0.65 for rCFVR, within the full range of coronary narrowings. Intracoronary blood flow velocity analysis could obviate the need for additional myocardial perfusion scintigraphy in the majority of patients.

Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables

OBJECTIVES

Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia.

BACKGROUND

There is limited information regarding the hemodynamic quantification of recruitable collateral vessels.

METHODS

Angiography of the donor coronary artery was performed before and during balloon coronary occlusion in 63 patients with one vessel disease. Patients were divided into groups of those with an absence of collateral vessels (group 1, n = 10), those with recruitable collateral vessels (group 2, n = 23) and those with spontaneously visible collateral vessels (group 3, n = 30). During balloon inflation the coronary wedge/aortic pressure ratio (Pw/Pao) was determined as were collateral blood flow velocity variables, using a 0.014" Doppler guide wire. Myocardial ischemia was defined as > or =0.1 mV ST-shift on a 12 lead electrocardiogram at 1 min coronary occlusion.

RESULTS

Myocardial ischemia was present in all patients of group 1, in 14 patients of group 2 and in 3 patients of group 3. Recruitable collateral flow without ischemia showed similar hemodynamic values as in group 3 while these values were similar to group 1 in regard to the presence of recruitable collateral vessels showing ischemia. Logistic regression analysis revealed both Pw/Pao and Vi(col) as independent predictors for the function of collateral vessels.

CONCLUSIONS

Hemodynamic variables of collateral vascular circulation are better markers of the functional significance of collateral vessels than is coronary angiography. The total collateral blood flow velocity integral and coronary wedge/aortic pressure ratio are good and independent predictors of the function of collateral vessels producing complementary information.

Two hour ambulation after coronary angioplasty and stenting with 6 F guiding catheters and low dose heparin

OBJECTIVE

To evaluate the feasibility and safety of ambulation of patients two hours after elective coronary angioplasty or stenting, or both.

METHODS

Coronary angioplasty and stenting were performed using 6 F guiding catheters by the femoral approach and a standard dose of heparin 5000 IU. There were no angiographic exclusion criteria except for planned atherectomy. Patients given oral anticoagulants or heparin were not eligible. All patients were given aspirin. Patients who underwent stent implantation also received ticlopidine 250 mg daily. The arterial sheath was removed immediately after the procedure. Haemostasis was achieved by manual compression and maintained with an inguinal compression bandage. Early ambulation was attempted after two hours of supine bed rest following removal of the bandage.

MAIN OUTCOME MEASURES

The incidence of bleeding at or during ambulation requiring compression and additional bed rest, and puncture site complications documented 48 hours after the procedure.

RESULTS

300 of 359 consecutive eligible patients were included for two hour ambulation. Stent implantation was performed in 32% of the procedures. The mean (SD) time to haemostasis was 9.6 (3.2) minutes. Bleeding at ambulation occurred in five patients (1.7%), and nine patients (3.0%) reached the secondary end point of haematoma > 5 x 5 cm at 48 hour follow up. All were treated conservatively without further sequelae. There was no late bleeding or vascular complications.

CONCLUSION

Ambulation two hours after elective balloon angioplasty or stent implantation with 6 F guiding catheters by the femoral route and low dose heparin is feasible and safe, with a low incidence of puncture site complications. This early ambulation protocol facilitates a short hospital stay.

Immediate and long-term effect of balloon angioplasty or stent implantation on the absolute and relative coronary blood flow velocity reserve

BACKGROUND

There is controversy regarding the immediate and long-term effects of PTCA on the coronary flow reserve.

METHODS AND RESULTS

A total of 54 patients with 1-vessel disease and normal left ventricular function were studied after balloon angioplasty (n=34) or stent implantation (n=20). Distal coronary blood flow velocity reserve (CFR) was defined as the ratio of adenosine-induced hyperemic versus baseline blood flow velocity with a 0.014-in Doppler guidewire. The relative CFR was defined as the ratio of the distal CFR and the reference CFR measured in the normal adjacent coronary artery. Hemodynamic and angiographic measurements were performed before and directly after balloon angioplasty or stent implantation and at 6-month follow-up. CFR after PTCA </=2.5 was defined as an impaired CFR. Immediately after PTCA, CFR improved toward the range of the reference artery CFR. In both the balloon-treated and the stent-treated groups, initial high CFR values decreased and impaired CFR values increased at follow-up toward the values of the reference CFR in patients without restenosis. Impaired CFR after balloon angioplasty (33%) or stent implantation (58%) in patients without restenosis was related to an increased baseline flow velocity that normalized at follow-up. Patients with an increase of CFR after stenting were characterized by an unaltered baseline flow velocity and an increased adenosine-induced hyperemic flow velocity.

CONCLUSIONS

An impaired CFR (</=2.5) is a frequent finding after balloon angioplasty or stent implantation as a result of a high baseline flow velocity. Normalization of impaired CFR at follow-up in patients without restenosis was associated with a decline of the baseline flow velocity after both balloon angioplasty and stent implantation, supporting the contention that this phenomenon relates to a slow recovery of autoregulation of the microvascular bed.