Endovascular Treatment of Penetrating Aortic Ulcers: Mid-term Results

OBJECTIVES

The aim of this study was to evaluate mid-term results of endovascular treatment of penetrating aortic ulcers.

METHODS

Between February 2000 and November 2006, 18 consecutive patients underwent endovascular treatment of the descending thoracic aorta (N=16) and abdominal infrarenal aorta (N=2) for penetrating aortic ulcer, in a single University Hospital. Data were prospectively collected and retrospectively analyzed. Mean follow-up was 41 months (range 4 to 77 months).

RESULTS

Technical success was achieved in all patients. No perioperative deaths occurred. No conversion to open repair or secondary procedures were required. Two patients died in the follow-up period for reasons not related to penetrating aortic ulcers. One type II endoleak was observed. It was still present, unchanged, twelve months after the procedure.

CONCLUSION

Endovascular treatment of penetrating aortic ulcers of the descending thoracic and infrarenal aorta were safe and effective in the mid-term in this small series of patients.

Potent Modulation of Intestinal Tumorigenesis inApcmin/+Mice by the Polyamine Catabolic Enzyme Spermidine/SpermineN1-acetyltransferase

Intracellular polyamine pools are homeostatically maintained by processes involving biosynthesis, catabolism, and transport. Although most polyamine-based anticancer strategies target biosynthesis, we recently showed that activation of polyamine catabolism at the level of spermidine/spermine N(1)-acetyltransferase-1 (SSAT) suppresses tumor outgrowth in a mouse prostate cancer model. Herein, we examined the effects of differential SSAT expression on intestinal tumorigenesis in the Apc(Min/+) (MIN) mouse. When MIN mice were crossed with SSAT-overproducing transgenic mice, they developed 3- and 6-fold more adenomas in the small intestine and colon, respectively, than normal MIN mice. Despite accumulation of the SSAT product, N(1)-acetylspermidine, spermidine and spermine pools were only slightly decreased due to a huge compensatory increase in polyamine biosynthetic enzyme activities that gave rise to enhanced metabolic flux. When MIN mice were crossed with SSAT knock-out mice, they developed 75% fewer adenomas in the small intestine, suggesting that under basal conditions, SSAT contributes significantly to the MIN phenotype. Despite the loss in catabolic capability, tumor spermidine and spermine pools failed to increase significantly due to a compensatory decrease in biosynthetic enzyme activity giving rise to a reduced metabolic flux. Loss of heterozygosity at the Apc locus was observed in tumors from both SSAT-transgenic and -deficient MIN mice, indicating that loss of heterozygosity remained the predominant oncogenic mechanism. Based on these data, we propose a model in which SSAT expression alters flux through the polyamine pathway giving rise to metabolic events that promote tumorigenesis. The finding that deletion of SSAT reduces tumorigenesis suggests that small-molecule inhibition of the enzyme may represent a nontoxic prevention and/or treatment strategy for gastrointestinal cancers.

Coronary artery fistulas: clinical consequences and methods of closure. A literature review

Coronary fistulas are uncommon anomalies of congenital and rarely iatrogenic etiology. Their clinical significance is mainly dependent on the severity of the left-to-right shunt they are responsible for. Symptoms, high-flow shunting and the occurrence of complications, only partially related to the magnitude of the shunt, are the main indications for their closure, especially in the adult population. Pediatric patients, even asymptomatic but presenting with electrocardiographic or chest X-ray abnormalities, should be treated in order to avoid the long-term complications related to the presence of the fistula. Treatment of adult asymptomatic patients with non-significant shunting is still a matter of debate. Surgery and direct epicardial or endocardial ligation were traditionally viewed as the main therapeutic method for the closure of coronary fistulas. Progress in the techniques of endoluminal intervention has led to fistula embolization using different devices including coils, balloons and chemicals. The success rate is good and the procedure-related morbidity acceptable.

Long-term prognosis of painless exercise-induced ischemia in stable patients with previous myocardial infarction

OBJECTIVES

This study was designed to better understand the functional correlates and the prognostic relevance of exercise-induced painless ischemia relative to painful ischemia in patients with stable coronary artery disease and previous myocardial infarction (MI).

BACKGROUND

The usefulness of exercise testing (ET) for predicting cardiac events, years after MI, although suggested and widely applied, is questionable. In particular, previous studies have reached conflicting conclusions as to whether exercise-induced painless ischemia is related to a less severe myocardial ischemia or to a different prognosis than painful ischemia.

METHODS AND RESULTS

Seven hundred sixty-six consecutive stable patients (mean age 57+/-8.6 years, 89% men) with previous MI (mean time from MI 2.8+/-0.75 years) who underwent a Bruce treadmill test and whose data were prospectively entered into our institutional database were enrolled. Patients were followed up for an average of 7+/-0.6 years. End points were (1) cardiac death, (2) cardiac death or nonfatal reinfarction (primary), (3) cardiac death, nonfatal reinfarction, or unstable angina (secondary), and (4) cardiac death, nonfatal reinfarction, unstable angina, or revascularization procedures (secondary, restricted). These patients were retrospectively classified into 4 groups according to exercise test results: (1) painless ischemia, 156 patients; (2) painful ischemia, 75 patients; (3) negative ET, 99 patients; and (4) nondiagnostic ET, the remaining 436 patients. Patients with painless ischemia had less functional impairment and less exercise ischemia than the symptomatic patients (longer exercise duration [P < .001], higher double product [P < .001], higher ischemic threshold [P < .001], and shorter time to ST normalization [P < .001]). Patients with painful ischemia had significantly (P < .0005) increased 6-year risk rates of secondary and restricted end points (49% and 64%, respectively) versus those with painless ischemia (28% and 35%), no inducible ischemia (25% and 27%), or nondiagnostic ET (32% and 37%). Adverse outcomes were mainly the result of higher incidence of unstable angina or revascularization procedures. At multivariate analysis, neither painless nor painful exercise-induced ischemia were independent predictors of end points.

CONCLUSIONS

Stable patients with previous MI represent a very low-risk population. In this subset, painless exercise-induced ischemia signifies less severe ischemia than the symptomatic one and has a limited prognostic power. Thus painless exercise-induced ischemia in stable patients with previous MI does not identify patients at increased risk.

Can exercise testing in patients with a history of myocardial infarction predict fatal and non-fatal reinfarction?

BACKGROUND AND OBJECTIVES

Exercise testing (ET) is the preferred initial strategy for risk stratification in patients who are able to exercise and have an interpretable electrocardiogram. However, although it is often suggested and widely applied, its usefulness years after myocardial infarction (MI) is questionable. Therefore, this study was designed to assess the value of exercise testing in predicting the risk of fatal or non-fatal reinfarction in patients with chronic stable coronary artery disease (CAD) due to old myocardial infarction.

METHODS

Our study involved 766 consecutive stable subjects [mean (SD) age 57 (8.6) years; male: 89%] with stable CAD due to old MI [mean time from MI: 2.8 (0.75) years], who underwent a Bruce treadmill test and whose data were prospectively entered into our institutional database. Patients were followed up for an average of 7 (0.6) years.

RESULTS

Reinfarction was observed in 62 patients; 54 non-fatal and 8 (13%) fatal. Relative risk (RR) of cardiac death for subjects with reinfarction was 4.02 [95% confidence interval (CI): 2.46 to 6.55]. Univariate predictors of fatal or non-fatal reinfarction were: multivessel disease (RR 7.99, CI 1.12 to 56.82), EF < 40% (RR 2.91, CI 1.64 to 7.17), ST depression on rest ECG (RR 2.4, CI 1.30 to 4.45), BP increase with exercise < 10 mmHg (RR 2.36, CI 1.41 to 3.93), BP/HR interaction < 10 mmHg + < 85% max (RR 2.16, CI 1.24 to 3.76). Markers of reduced risk of recurrence included low-risk Duke Treadmill Score (RR 0.55, CI 0.33 to 0.91) and EF > or = 40% (RR 0.34, CI 0.19 to 0.60). A Cox regression model with clinical and exercise parameters detected ST depression on rest ECG (RR 1.47, CI 1.07 to 2.02), BP increase with exercise < 10 mmHg (RR 1.41, CI 1.07 to 1.87), low-risk Duke Treadmill Score (RR 0.79, CI 0.60 to 1.02). A model with coronary anatomy and ejection fraction was also able to identify multivessel disease (RR 2.95, CI 1.43 to 6.09), EF < 40% (RR 1.62, CI 1.17 to 2.25) and BP increase with exercise < 10 mmHg (RR 2.53, CI 1.35 to 4.71).

CONCLUSIONS

Stable patients with a history of MI represent a very low-risk population in whom reinfarction continues to have a severe prognosis. ET is unable to identify subjects in whom there is a risk of recurrence, especially if only ischemic parameters are evaluated (in this setting, a clinical or anatomic risk stratification may be better). The application of the Duke Treadmill Score could help to identify a very low-risk group in which no additional testing is required. Therefore, routine ET in stable patients with a history of MI is better at identifying a very low-risk group than in predicting recurrence.

[ST segment depression during recovery after treadmill exercise test in stable patients with previous myocardial infarction]

BACKGROUND

The significance of exercise-induced ST segment depression is well known while limited data are available on the clinical/prognostic power of ST depression occurring only during recovery. Aim of the study was to clarify the clinical/prognostic value of "recovery only" ST depression in stable patients late from myocardial infarction (AMI) and to determine whether the addition of recovery data to exercise parameters improves the interpretation of exercise test.

METHODS

From a population of 766 consecutive patients (mean age: 57.2 +/- 8.6 yrs.; male: 89%) who underwent a Bruce Treadmill test at least 1 year after a Q wave AMI and whose exercise data were prospectively entered in the database of our Institution, 4 different Groups were identified: 1) 99 patients with a negative exercise test; 2) 53 patients with "exercise only" ST depression; 3) 140 patients with "exercise and recovery" ST depression; 4) 31 patients with "recovery only" ST depression. The main clinical and exercise data and a cardiac follow-up (average mean length: 1530 +/- 600 day) were evaluated by one-way analysis of variance, Bonferroni T-test, chi-square, relative risk (RR) with 95% confidence intervals (CI), Kaplan-Meler method and log-rank.

RESULTS

Baseline clinical parameters were similar in the 4 Groups except for older age in Group 3 compared to Group 2 (< 0.05) and higher prevalence of anterior AMI in Group 4 compared to others (= 0.004). Patients with exercise and recovery ST depression or with "recovery only" ST depression had significantly less exercise tolerance than patients with negative exercise test or "exercise only" ST depression [exercise duration (< 0.05, Group 1 vs. 3, vs. 4; Group 2 vs. 3), peak rate pressure product (< 0.05), maximal heart rate (< 0.05; Group 1 vs. 2; vs. 3; vs. 4)]. Exercise-induced ST depression was higher and angina was significantly more frequent in patients with exercise and recovery ST depression as well as an high Mark's risk score (< 0.001). Only patients with exercise and recovery ST depression demonstrated significantly higher risk of overall mortality (RR: 1.35, CI: 1.04-1.74), unstable angina (RR: 1.34, CI: 1.09-1.65) or revascularisation procedures (RR: 1.51, CI: 1.25-1.83). Relative risk of patients with "recovery only" ST depression was similar to that of subjects with "exercise only" ST depression.

CONCLUSIONS

In stable patients with old Q wave AMI, "recovery only" ST depression is rate, but does represent a true sign of ischemia. It could be associated with indirect indexes of worse ventricular function. The prognostical power of "recovery only" ST depression is mild, although similar to that of "exercise only" ST depression. Moreover the presence of ST depression not only during exercise but also during the recovery phase identifies patients with more severe prognosis. Therefore the inclusion of findings from the recovery phase in the analysis of the exercise test could increase the predictive power of the test itself.