Eugene B. Wu

Tissue Doppler velocity is superior to displacement and strain mapping in predicting left ventricular reverse remodelling response after cardiac resynchronisation therapy

Objective: To compare the values of three different forms of tissue Doppler imaging (TDI) processing in predicting left ventricular (LV) reverse remodelling—namely, tissue velocity, displacement and strain mapping. Design: Standard echocardiography with TDI was performed before and 3 months after cardiac resynchronisation therapy (CRT). Setting: University teaching hospital. Patients: 55 patients with heart failure who received CRT and were followed up for at least 3 months were recruited. Interventions: During off-line analysis, the time to peak systolic velocity in the ejection phase, time to peak positive displacement and time to peak negative strain were measured in the six basal, six mid-segmental model. Parameters of systolic asynchrony derived by velocity, displacement and strain mapping were correlated with percentage reduction in LV end systolic volume (LVESV) and absolute gain in ejection fraction (EF). Results: Among the three TDI processing technologies, all parameters of tissue velocity correlated with LV reverse remodelling (r  = −0.49 to r  =  −0.76, all p < 0.001), but the predictive value was strongest in models with 12 LV segments. For displacement mapping, only the two parameters that included 12 LV segments correlated modestly with reduction in LVESV (r  =  −0.36, p < 0.05) and gain in EF. However, none of the strain mapping parameters predicted a favourable echocardiographic response. The receiver operating characteristic (ROC) curve areas were higher for parameters of tissue velocity based on 12 LV segments (ROC areas 0.88 and 0.94) than the corresponding areas derived from displacement mapping (ROC areas 0.72 and 0.71). Conclusion: Tissue velocity parameters of systolic asynchrony are superior to those of displacement and strain mapping in predicting LV reverse remodelling response after CRT.

Improvement of left ventricular myocardial short-axis, but not long-axis function or torsion after cardiac resynchronisation therapy: an assessment by two-dimensional speckle tracking

Aims: To evaluate whether short-axis function plays a part in determining left ventricular (LV) geometric and functional improvement after cardiac resynchronisation therapy (CRT). Methods and results: 39 patients who received CRT were enrolled. 2D speckle tracking echocardiography was performed at baseline and three months after CRT to assess mean systolic circumferential (ϵ-circum), radial (ϵ-radial) and longitudinal (ϵ-long) strain and torsion. Responders of reverse remodelling (n = 21) had higher baseline mean ϵ-circum than non-responders (p<0.05), who also had improvement in mean ϵ-circum and mean ϵ-radial (both p<0.05) after CRT. Also, the increase in mean ϵ-circum correlated with increase in ejection fraction (r = 0.57, p<0.001) and decrease in mid-cavity width (r = −0.52, p = 0.001). A baseline mean ϵ-circum of ⩾6.5% predicted a gain in ejection fraction ⩾5%, with a sensitivity of 73% and a specificity of 71%. The baseline ϵ-long was not different between the two groups, and remained unchanged after CRT. The torsion did not improve in responders, but was worsened in non-responders (p<0.05). Conclusions: The improvement of LV short-axis function but not long-axis function or torsion contributes to the improvement in LV global function and geometry at three-month follow up. A relatively preserved mean ϵ-circum of ⩾6.5% might be useful to predict favourable responses after CRT.

Retrograde chronic total occlusion intervention: tips and tricks.

Retrograde approach via collateral channels in coronary angioplasty for chronic total occlusion (CTO) can improve the success rate. Most interventionists will meet a few cases where the retrograde approach will provide unequaled advantages, but many are held back from taking retrograde approach by lack of proper equipment and expertise. In this article, we give detail description of techniques to shorten the guiding catheter, to traverse the collateral channels, and to cross the CTO. We also illustrate the difficulties in collateral channel crossing with different examples providing a basic guide for case selection purposes. We hope that many others would find rewardingly successful cases of retrograde approach CTO percutaneous coronary intervention, as in our experience.

Left ventricular systolic and diastolic dyssynchrony in coronary artery disease with preserved ejection fraction

The present study aims to evaluate LV (left ventricular) mechanical dyssynchrony in CAD (coronary artery disease) with preserved and depressed EF (ejection fraction). Echocardiography with TDI (tissue Doppler imaging) was performed in 311 consecutive CAD patients (94 had preserved EF > or =50% and 217 had depressed EF <50%) and 117 healthy subjects to determine LV systolic and diastolic dyssynchrony by measuring Ts-SD (S.D. of time to peak myocardial systolic velocity during the ejection period) and Te-SD (S.D. of time to peak myocardial early diastolic velocity during the filling period) respectively, using a six-basal/six-mid-segmental model. In CAD patients with preserved EF, both Ts-SD (32.2+/-17.3 compared with 17.7+/-8.6 ms; P<0.05) and Te-SD (26.2+/-13.6 compared with 20.3+/-8.1 ms; P<0.05) were significantly prolonged when compared with controls, although they were less prolonged than CAD patients with depressed EF (Ts-SD, 37.8+/-16.5 ms; and Te-SD, 36.0+/-23.9 ms; both P<0.005). Patients with preserved EF who had no prior MI (myocardial infarction) had Ts-SD (32.9+/-17.5 ms) and Te-SD (28.6+/-14.8 ms) prolonged to a similar extent (P=not significant) to those with prior MI (Ts-SD, 28.4+/-16.8 ms; and Te-SD, 25.5+/-15.0 ms). Patients with class III/IV angina or multi-vessel disease were associated with more severe mechanical dyssynchrony (P<0.05). Furthermore, the majority of patients with mechanical dyssynchrony had narrow QRS complexes in those with preserved EF. This is in contrast with patients with depressed EF in whom systolic and diastolic dyssynchrony were more commonly associated with wide QRS complexes. In conclusion, LV mechanical dyssynchrony is evident in CAD patients with preserved EF, although it was less prevalent than those with depressed EF. In addition, mechanical dyssynchrony occurred in CAD patients without prior MI and narrow QRS complexes.

Relation of Left Ventricular Systolic Dyssynchrony in Patients With Heart Failure to Left Ventricular Ejection Fraction and to QRS Duration

Left ventricular (LV) systolic dyssynchrony is an important pathologic mechanism in patients with heart failure (HF). However, the prevalence of intraventricular dyssynchrony in patients with different LV ejection fractions (EFs) is unknown. This study evaluated 402 consecutive patients with HF (mean age 64.99 +/- 13.15 years, 72.4% men) and 120 healthy controls. Dyssynchrony indexes included the SD of the time to peak systolic velocity (Ts) in ejection phase in the 12-segmental model (Ts-SD) and the difference in Ts between basal septal and basal lateral segments (Ts-Septal-Lateral) using tissue Doppler imaging. Patients were divided into 3 groups according to LVEF (LVEF <20%, >20% to 35%, and >35% to 50%) and compared with healthy controls. Both indexes were significantly higher in all 3 LVEF groups compared with controls (p <0.0001). Based on the established cut-off values, systolic dyssynchrony was equally prevalent in all 3 LVEF groups and was 67%, 62%, and 55% using Ts-SD and 38%, 36%, and 35% using Ts-Septal-Lateral, respectively. However, the prevalence of systolic dyssynchrony was higher using Ts-SD than Ts-Septal-Lateral (chi-square = 94.43, p <0.001). Conversely, the prevalence of electrical dyssynchrony, defined as a >120-ms QRS duration, decreased significantly with increasing LVEF (44%, 35%, and 16%; chi-square 5.60, p <0.001). In conclusion, the prevalence of mechanical systolic dyssynchrony was independent of severity of LV systolic dysfunction. This may implicate the potential role of cardiac resynchronization therapy for those with LVEF of 35% to 50%, in particular when systolic dyssynchrony is present.

Management of diastolic heart failure – a practical review of pathophysiology and treatment trial data

The lack of large randomised controlled trials to guide therapy in diastolic heart failure causes some difficulties for evidence‐based medicine practising clinicians. Traditionally, treatments for systolic heart failure have been highjacked for diastolic heart failure without much proof of benefit. However, recent studies have began to provide some evidence base for our practice. Betablockers and angiotensin receptor antagonists have recently been shown to reduce hospitalisation in large randomised controlled trials. Diuretic based antihypertensive regimes have been shown to reduce heart failure by 50%. Left ventricular hypertrophy regression is likely to be a good surrogate endpoint for diastolic heart failure, although definitive proof for this is not yet available. Angiotensin receptor antagonists, ACEI, calcium channel blockers, diuretics and aldosterone blockers have all been shown to cause left ventricular hypertrophy regression.

Left main stem rupture caused by methicillin resistant Staphylococcus aureus infection of left main stent treated by covered stenting

Coronary artery infection after angioplasty or stent implantation is a rare and dreaded complication of percutaneous coronary intervention. 80% of the cases are due to Staphylococcus aureus. About half the cases lead to rupture or perforation of the coronary artery while the other half presents as abscesses or aneurysms. Surgical treatment is the conventional therapeutic modality but it carries a high mortality. We report a case of a high risk patient who had methicillin resistant Staphylococcus aureus infection of left main stem stent leading to rupture and pseudoaneurysm formation that is successfully treated with stent graft.

Comparison of left ventricular reverse remodeling induced by cardiac contractility modulation and cardiac resynchronization therapy in heart failure patients with different QRS durations.

BACKGROUND Cardiac contractility modulation (CCM) is a new device-based therapy for advanced systolic heart failure with normal QRS duration and therefore not suitable for cardiac resynchronization therapy (CRT). Left ventricular (LV) reverse remodeling was reported in patients treated with CCM or CRT, however, the extent of response was not compared. METHODS This observational study consisted of three groups of patients with symptomatic heart failure and LV ejection fraction <35% despite optimal medical therapy. Group 1 included those received CCM with a QRS duration <120 ms (n=33), Group 2 included those received CRT with a QRS duration of 120-150 ms (n=43), and Group 3 included those received CRT with a QRS duration >150 ms (n=56). LV end-systolic volume (LVESV) was measured at baseline and 3 months later. RESULTS Age, gender, etiology of heart failure and baseline ejection fraction were comparable. A significant LV reverse remodeling was observed in each group. The degree of LVESV reduction was similar between Group 1 and Group 2 (-11.3 ± 1 1.8 vs. -13.6 ± 18.3%, p=0.833), however, it was greater in Group 3 (-25.0 ± 18.0%, both p<0.01). By using the reduction ≥ 15%, the responder rate was not different between Group 1 (39%) and Group 2 (42%), but significantly higher in Group 3 (68%) (χ(2)=9.514, p=0.009). CONCLUSION CCM exhibited a similar LV reverse remodeling response to CRT for patients with a mildly prolonged QRS, though the effect was less strong when compared to CRT for patients with a very wide QRS.

A review of the management of patients after percutaneous coronary intervention.

The exponential increase in the numbers of percutaneous coronary interventions (PCIs) has led to many clinicians having to care for post‐PCI patients. We review the management of early problems seen in post‐PCI patients, such as vascular access site complications, contrast nephropathy, drug‐induced thrombocytopaenia and chest pain. The management of possible restenosis and the use of stress testing are discussed. The complications from dual antiplatelet therapy are addressed. The prognosis of the post‐PCI patient, the implications of co‐existent heart failure and the newer technologies of implantable defibrillator and cardiac resynchronisation therapy are reviewed. We conclude by emphasising the importance of secondary prevention by risk factor modification as well as the communication between the clinician and the cardiologist.

Transcatheter aortic valve implantation: the transaortic approach

Background Transcatheter aortic valve implantation has been established as a safe and effective treatment option for patients at high or prohibitive surgical risk. However, some patients may not be suitable for the transfemoral approach due to severe iliofemoral disease or aneurysmal disease of the thoracoabdominal aorta. The aim of this case series was to evaluate the feasibility and clinical outcomes of the transaortic approach. Methods From May 2015 to June 2016, 5 patients (mean age 78.4 ± 3.9 years) with severe symptomatic aortic stenosis underwent transaortic transcatheter aortic valve implantation after a heart team discussion. They were considered to be at high surgical risk and ineligible for the transfemoral approach due to iliofemoral or thoracoabdominal aortic disease. Results A CoreValve Evolut R was successfully deployed in all 5 patients. We performed 4 right mini-parasternal incisions and one J-incision partial sternotomy. None of the patients required permanent pacemaker implantation, one required reopening of the mini-parasternal incision for postoperative bleeding. Follow-up echocardiography one month after the procedure showed improvement in the mean aortic gradient (from 63.2 to 8.3 mm Hg) and aortic valve area (from 0.62 to 2.2 cm2). None of the patients had more than mild paravalvular leakage. There was no intraoperative or 30-day mortality. Conclusion Transaortic transcatheter aortic valve implantation is a safe and feasible option for patients with severe aortic stenosis who are considered unsuitable for transfemoral aortic valve implantation.