The evolution of coronary stents.

INTRODUCTION: Percutaneous coronary intervention (PCI) is 40 years old this year. From its humble beginnings of experimental work, PCI has transitioned over years with coronary artery stenting now a standard medical procedure performed throughout the world. Areas covered: The conversion from plain old balloon angioplasty (POBA) to the present era of drug eluting stents (DES) has been driven by many technological advances and large bodies of clinical trial evidence. The journey to present day practice has seen many setbacks, such as acute vessel closure with POBA; rates of instant restenosis with bare metal stents (BMS) and more recently, high rates of stent thrombosis with bioabsorbable platforms. This work discusses POBA, why there was a need for BMS, the use of inhibiting drugs to create 1st generation DES, the change of components to 2nd generation DES, the use of absorbable drug reservoirs and platforms, and possible future directions with Prohealing Endothelial Progenitor Cell Capture Stents. Expert commentary: This paper reviews the evolution from the original pioneering work to modern day practice, highlighting landmark trials that changed practice. Modern day contemporary practice is now very safe based on the latest drug eluting stents and supported by large datasets.

Management and Prevention of Saphenous Vein Graft Failure: A Review.

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Interatrial pressure gradients during simulated obstructive sleep apnea: a catheter-based study.

OBJECTIVES: We set to measure the interatrial pressure gradient during simulated obstructive sleep apnea (OSA). BACKGROUND: OSA occurs when a sleeping patient attempts to inhale against an obstructed airway. How this event affects the interatrial pressure gradient has not been defined. We hypothesized that simulated OSA in a conscious subject (Mueller maneuver [MM], inspiration against obstruction) would promote increased right-to-left pressure gradient, and then the substrate for right-to-left atrial shunting. METHODS: Selected patients underwent simultaneous measurement of airway and atrial pressures (both left and right atrium [LA, RA]) using high-fidelity micromanometry at rest, during MM, and during VM, during right heart catheterization. RESULTS: Ten patients (age 55 ± 11 years, two women) were successfully studied. During the onset of MM, RA pressure transiently but consistently exceeded LA pressure in response to the steep decline in intrathoracic pressure (maximum RA-LA pressure gradient increased from 0.1 ± 1.4 mm Hg at baseline to 7.0 ± 4.3 mm Hg during MM, P < 0.001). The maximum right-to-left atrial pressure gradient during Mueller maneuver was higher than that achieved during the Valsalva maneuver release (P < 0.007). CONCLUSIONS: The onset of MM increased right-to-left pressure gradient across the atrial septum, likely as a result of greater blood return to the RA from extrathoracic veins. The RA-LA pressure gradient achieved during MM was greater than that observed during VM. These findings delineate the hemodynamic substrate for right to left shunting during OSA.

The mechanics of left ventricular dysfunction in patients with Churg-Strauss syndrome.

BACKGROUND: Heart is frequently involved in Churg-Strauss syndrome (CSS). However, the mechanics of left ventricular (LV) dysfunction in CSS has not been studied. OBJECTIVE: To assess the mechanics of LV function and to characterize the contribution of longitudinal, circumferential and rotational deformation to LV dysfunction in CSS. METHODS: We enrolled 22 CSS patients (eight males, mean age 43.2 ± 9.5 years) in remission of their disease and 22 sex- and age-matched healthy subjects. All patients underwent conventional and two-dimensional speckle-tracking echocardiography. Global longitudinal, circumferential and rotational deformation parameters were calculated. RESULTS: CSS subjects demonstrated lower LV ejection fraction (EF) than controls (56.6 ± 15.0% vs 63.8 ± 3.4%; P < 0.05). When compared to those with LVEF ≥ 50% (n = 14), CSS patients with LVEF < 50% (n = 7) had decreased global peak-systolic longitudinal and circumferential strain/strain rate (all P < 0.001) and tended to have lower global peak-systolic radial strain (P = 0.05). There were no differences between these two subgroups in global peak-systolic radial strain rate and LV twist/torsion. When comparing individual systolic and diastolic parameters early diastolic longitudinal and circumferential strain rate demonstrated the highest correlation with corresponding global longitudinal and circumferential peak-systolic strain/strain rate (r < -0.80, P < 0.001 for all correlations). CONCLUSIONS: In CSS LV systolic dysfunction strongly correlates with longitudinal and circumferential, but not radial or rotational systolic components, indicating that impaired LV systolic function may result predominantly from impaired contraction of inner and middle, but not outer myocardial fiber layers. The spatial correspondence between systolic and diastolic deformation parameters suggests the similar impact of pathologic process on systolic and diastolic function in CSS.

Extent of RV dysfunction and myocardial infarction assessed by CMR are independent outcome predictors early after STEMI treated with primary angioplasty.

OBJECTIVES: The aim of this study was to assess the prognostic value of right ventricular (RV) involvement diagnosed by cardiac magnetic resonance (CMR) early after ST-elevation myocardial infarction (STEMI). BACKGROUND: CMR allows accurate and reproducible RV assessment. However, there is a paucity of data regarding the prognostic value of RV involvement detected by CMR early after STEMI. METHODS: Ninety-nine patients (77 men, mean age 57 ± 11 years) who underwent CMR 3 to 5 days after STEMI treated with primary angioplasty were followed for 1,150 ± 337 days for cardiac events (cardiac death, nonfatal myocardial infarction [MI], and hospitalizations due to decompensated heart failure). Cox proportional hazards model was applied in stepwise forward fashion to identify outcome predictors. Event-free survival was estimated by Kaplan-Meier method and compared between groups by the log-rank test. RESULTS: Cardiac events occurred in 34 patients (7 cardiac deaths, 8 MIs, 26 hospitalizations). By multivariable analysis, the independent outcome predictors were left ventricular (LV) MI transmurality index (hazard ratio: 1.03 per 1%; 95% confidence interval: 1.01 to 1.04; p = 0.001), RV ejection fraction (RVEF) (hazard ratio: 1.46 per 10% decrease; 95% confidence interval: 1.05 to 2.02; p = 0.03), and RVMI extent (hazard ratio: 1.50 per each infarcted RV segment; 95% confidence interval: 1.11 to 2.01; p = 0.007). Compared with clinical data (global chi-square = 5.2), LV ejection fraction [LVEF] (global chi-square = 11.1), RVEF (global chi-square = 17.1), LVMI transmural extent (global chi-square = 26.0), and RVMI extent (global chi-square = 34.9) improved outcome prediction in sequential Cox model analysis (p < 0.05 for all steps). RVEF stratified risk in patients with LVEF <40% in whom the 4-year event-free survival was 66.7% for RVEF ≥40% and 40.0% for RVEF <40% (p < 0.05). CONCLUSIONS: The extent of RVMI and RV dysfunction assessed early after STEMI are independent outcome predictors, which provide incremental prognostic value to clinical data, LV systolic function, and infarct burden. Measurement of RVEF may be particularly useful to stratify risk in patients with depressed LV function after STEMI.