Context

Surgical treatment of aortic root aneurysm in Marfan syndrome (MFS) patients.

Objective

To compare results of total root replacement versus valve-sparing aortic root replacement in MFS patients.

Data Sources

PubMed, Embase and Cochrane library were searched from January 1966 until February 2010 looking for papers reporting on aortic root operations in MFS patients. 530 studies were retrieved.

Study Selection

Finally, 11 publications were enrolled. Inclusion criteria were observational studies reporting valve-related morbidity and mortality after total root replacement (TTR) and/or valve-sparing root replacement (VSRR) in patients with MFS and study size n≥30, reflecting the centre’s experience.

Data Extraction

Data obtained from papers reporting both TRR and VSRR cohorts were analysed separately. In case of multiple publications, the most recent and complete report was selected. If the total number of patient-years was not provided, we calculated it by multiplying the number of hospital survivors with the mean follow-up duration of that study.

Results

Overall, 1385 patients were analysed (972 patients had TTR and 413 patients had VSRR). Reintervention rate was 0.3%/year (95% CI 0.1 to 0.5) versus 1.3%/year (95% CI 0.3 to 2.2) (p=0.02) and thromboembolic events rate was 0.7%/year (95% CI 0.5 to 0.9) versus 0.3%/year (95% CI 0.1 to 0.6) (p=0.01) after TRR and VSRR, respectively. When composite valve-related events were compared, no difference existed between the two surgical strategies (p=0.41). Among patients undergoing VSRR, reimplantation was associated with a reduced rate of reintervention compared with remodelling (0.7%/year vs 2.4%/year, p=0.02).

Conclusions

VSRR may represent a valuable option for patients with MFS with aortic aneurysm. However, this technique should be used with caution in patients with valve characteristics at risk for decreased durability.

Drug eluting stents (DES) have undoubtedly been efficacious in attenuating restenosis. There is comparatively little in vivo data however, on the influence of DES and the powerful cytostatic agents they employ on arterial healing in patients. Even in the early DES trials, intravascular ultrasound (IVUS) demonstrated adverse (expansive) arterial remodelling with late acquired malapposition of stent struts, though the clinical relevance of this was overlooked until associations with late stent thrombosis (LST) were demonstrated.1

Autopsy studies of patients dying of late DES thrombosis show a pattern of delayed arterial healing characterised by incomplete re-endothelialisation and persistence of fibrin. A high ratio (>30%) of stent struts uncovered by any tissue in any one examined section was the morphometric feature most predictive of both incomplete re-endothelialisation and the occurrence of LST.2 Prior technology has not allowed us to study this relationship in vivo as up to 67%…

Elective root replacement of the ascending aorta in people with Marfan syndrome has been established practice for more than 25 years; it greatly reduces the risk they face from fatal aortic dissection.1 Now that low perioperative risk is assured and long-term survival is expected, long-term consequences and the durability of the surgery have become important considerations. The question for people with Marfan syndrome, their families and their surgeons is whether to choose the valve-sparing or valve-replacement forms of surgery. This question is at the core of the systematic review and meta-analysis published in this issue of Heart (see page 955).2 The decision as to which option to prefer is dominated by a trade-off between these competing risks; the analysis presented informs the choice but does not make it any easier. How would an individual patient weigh the risk of stroke versus a given possibility…

Background

The circadian clock influences a number of cardiovascular (patho)physiological processes including the incidence of acute myocardial infarction. A circadian variation in infarct size has recently been shown in rodents, but there is no clinical evidence of this finding.

Objective

To determine the impact of time-of-day onset of ST segment elevation myocardial infarction (STEMI) on infarct size.

Methods

A retrospective single-centre analysis of 811 patients with STEMI admitted between 2003 and 2009 was performed. Infarct size was estimated by peak enzyme release. The relationship between peak enzyme concentrations and time-of-day were characterised using multivariate regression splines. Time of STEMI onset was divided into four 6-hour periods in phase with circadian rhythms.

Results

Model comparisons based on likelihood ratio tests showed a circadian variation in infarct size across time-of-day as evaluated by peak creatine kinase (CK) and troponin-I (TnI) concentrations (p=0.015 and p=0.012, respectively). CK and TnI curves described similar patterns across time, with a global maximum in the 6:00–noon period and a local minimum in the noon–18:00 period. Infarct size was largest in patients with STEMI onset in the dark-to-light transition period (6:00–noon), with an increase in peak CK and TnI concentrations of 18.3% (p=0.031) and 24.6% (p=0.033), respectively, compared with onset of STEMI in the 18:00–midnight period. Patients with anterior wall STEMI also had significantly larger infarcts than those with STEMI in other locations.

Conclusions

Significant circadian oscillations in infarct size were found in patients according to time-of-day of STEMI onset. The infarct size was found to be significantly larger with STEMI onset in the dark-to-light transition period (6:00–noon). If confirmed, these results may have a significant impact on the interpretation of clinical trials of cardioprotective strategies in STEMI.

Background

Recent studies have examined haemodynamic changes with stressors such as isometric handgrip and rapid atrial pacing in heart failure with preserved ejection fraction (HFpEF), but little is known regarding left ventricular (LV) pressure–volume responses during dynamic exercise.

Objective

To assess LV haemodynamic responses to dynamic exercise in patients with HFpEF.

Methods

Twenty subjects with normal ejection fraction (EF) and exertional dyspnoea underwent invasive haemodynamic assessment during dynamic exercise to evaluate suspected HFpEF.

Results

LV end-diastolic pressure was elevated at rest (>15 mm Hg, n=18) and with exercise (≥20 mm Hg, n=20) in all subjects, consistent with HFpEF. Heart rate (HR), blood pressure, arterial elastance and cardiac output increased with exercise (all p<0.001). Minimal and mean LV diastolic pressures increased by 43–56% with exercise (both p<0.0001), despite a trend towards a reduction in LV end-diastolic volume (p=0.08). Diastolic filling time was abbreviated with increases in HR and the proportion of diastole that elapsed prior to estimated complete relaxation increased (p<0.0001), suggesting inadequate relaxation reserve relative to the shortening of diastole. LV diastolic chamber elastance acutely increased 50% during exercise (p=0.0003). Exercise increases in LV filling pressures correlated with changes in diastolic relaxation rates, chamber stiffness and arterial afterload but were not related to alterations in preload volume, HR or cardiac output.

Conclusion

In patients with newly diagnosed HFpEF, LV filling pressures increase during dynamic exercise in association with inadequate enhancement of relaxation and acute increases in LV chamber stiffness. Therapies that enhance diastolic reserve function may improve symptoms of exertional intolerance in patients with hypertensive heart disease and early HFpEF.