Faculty Bibliography

BACKGROUND: Whether myocardial perfusion grade (MPG) following late recanalization of infarct-related arteries (IRAs) predicts left ventricular (LV) function recovery beyond the acute phase of myocardial infarction (MI) is unknown. METHODS AND RESULTS: The Total Occlusion Study of Canada-2 enrolled stable patients with a persistently occluded IRA beyond 24 hours and up to 28 days post-MI. We studied the relationship between the initial MPG and changes in LV function and volume as well as the change in MPG from immediate post-percutaneous coronary intervention (PCI) to 1 year in 139 PCI patients with thrombolysis in myocardial infarction grade 3 epicardial flow post-PCI and with paired values grouped into impaired or good MPG groups (MPG 0/1 or MPG 2/3). MPG 0/1 patients were more likely to have received thrombolytic therapy and to have a left anterior descending IRA. They had lower blood pressure and LV ejection fraction (LVEF) and a higher heart rate and systolic sphericity index at baseline. Changes in the MPG 0/1 and MPG 2/3 groups from baseline to 1 year were LVEF, 3.3+/-9.0% and 4.8+/-8.9% (P=0.42); LV end-systolic volume index (LVESVI), -1.1+/-9.2 and -4.7+/-12.3 mL/m(2) (P=0.25); LV end-diastolic volume index (LVEDVI), 0.08+/-19.1 and -2.4+/-22.2 mL/m(2) (P=0.67); and SDs/chord for infarct zone wall motion index (WMI), 0.38+/-0.70 and 0.84+/-1.11 (P=0.01). By covariate-adjusted analysis, post-PCI MPG 0/1 predicted lower WMI (P<0.001), lower LVEF (P<0.001), and higher LVESVI (P<0.01) but not LVEDVI at 1 year. Of the MPG 0/1 patients, 60% were MPG 2 or 3 at 1 year. CONCLUSIONS: Preserved MPG is present in a high proportion of patients following late PCI of occluded IRAs post-MI. Poor MPG post-PCI frequently improves MPG over 1 year. MPG graded after IRA recanalization undertaken days to weeks post MI is associated with LV recovery, indicating that MPG determined in the subacute post-MI period remains a marker of viability. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00025766

Patients from the Indian subcontinent have a distinct cardiovascular risk profile with profound health consequences. South Asians tend to develop more severe coronary artery disease at a younger age, and may also suffer from earlier myocardial infarction and heart failure. The genesis of this risk is multi-factorial. One important culprit is increased insulin resistance, possibly due to recently identified genetic polymorphisms. Another possible explanation is subclinical inflammation and a prothrombotic environment, as evidenced by increased levels of homocysteine, plasminogen activator inhibitor-1, and fibrinogen. The lipid profile of South Asians may play a role, as this population is known to have elevated levels of lipoprotein (a), as well as lower levels of HDL. In addition, this HDL may be dysfunctional, as this population may have a higher prevalence of low levels of HDL2b, as well as an increased preponderance of smaller HDL. Current guidelines for primary and secondary prevention have not reflected our growing insight into the unique characteristics of the South Asian population, and may need to evolve to reflect our knowledge

BACKGROUND: A substantial minority of patients with acute coronary syndromes (ACS) do not have a diameter stenosis of any major epicardial coronary artery on angiography ('no obstruction at angiography') of >/= 50%. We examined the frequency of this finding and its relationship to race and sex. HYPOTHESIS: Among patients with myocardial infarction, younger age, female sex and non-white race are associated with the absence of obstructive coronary artery disease at angiography. METHODS: We reviewed the results of all angiograms performed from May 19, 2006 to September 29, 2006 at 1 private (n = 793) and 1 public (n = 578) urban academic medical center. Charts were reviewed for indication and results of angiography, and for demographics. RESULTS: The cohort included 518 patients with ACS. There was no obstruction at angiography in 106 patients (21%), including 48 (18%) of 258 patients with myocardial infarction. Women were more likely to have no obstruction at angiography than men, both in the overall cohort (55/170 women [32%] vs 51/348 men [15%], P < 0.001) and in the subset with MI (29/90 women [32%] vs 19/168 men [11%], P < 0.001). Black patients were more likely to have no obstruction at angiography relative to any other subgroup (24/66 [36%] vs 41/229 [18%] Whites, 31/150 [21%] Hispanics, and 5/58 [9%] Asians, P = 0.001). Among women, Black patients more frequently had no obstruction at angiography compared with other ethnic groups (16/27 [59%] vs 17/59 [29%] Whites, 17/60 [28%] Hispanics, and 3/19 [6%] Asians, P = 0.001). CONCLUSIONS: A high proportion of a multiethnic sample of patients with ACS were found to have no stenosis >/= 50% in diameter at coronary angiography. This was particularly common among women and Black patients.

In the Occluded Artery Trial (OAT), percutaneous coronary intervention (PCI) of an infarct-related artery on days 3 to 28 after acute myocardial infarction was of no benefit compared to medical therapy alone. The present analysis was conducted to determine whether PCI might provide benefit to the subgroup of higher risk patients with a depressed ejection fraction (EF). Of 2,185 analyzed patients (age 58.6 +/- 11.0 years) with infarct-related artery occlusion on days 3 to 28 after acute myocardial infarction in the Occluded Artery Trial, 1,094 were assigned to PCI and 1,091 to medical therapy. The primary end point was a composite of death, reinfarction, and New York Heart Association class IV heart failure. The outcomes were analyzed by EF (first tertile, EF < or =44%, vs second and third tertiles combined, EF >44%). Interaction of the treatment effect with EF on the study outcomes were examined using the Cox survival model. The 5-year rates of the primary end point (death, reinfarction, or New York Heart Association class IV heart failure) were not different in either subgroup (PCI vs medical therapy, hazard ratio 1.25, 99% confidence interval 0.83 to 1.88, for EF < or =44%; hazard ratio 0.98, 99% confidence interval 0.64 to 1.50, for EF >44%). However, in patients with an EF >44%, PCI reduced the rate of subsequent revascularization (p = 0.004, interaction p = 0.05). In conclusion, optimal medical therapy remains the overall treatment of choice for stable patients with a persistent total occlusion of the infarct-related artery after acute myocardial infarction, irrespective of the baseline EF. In patients with normal or moderately impaired left ventricular contractility, PCI reduced the need for subsequent revascularization but did not otherwise improve outcomes

A decrease in mechanical complications after ST-elevation myocardial infarction may have contributed to improved survival rates associated with reperfusion by primary percutaneous coronary intervention (PCI). Mechanical complications occurred in 52 of 5,745 patients (0.91%) in the largest reported randomized trial in which primary PCI was the reperfusion strategy. The frequencies were 0.52% (30) for cardiac free-wall rupture (tamponade), 0.17% (10) for ventricular septal rupture, and 0.26% (15) for papillary muscle rupture (3 patients had 2 complications). Ninety-day survival rates were 37% (11) for cardiac free-wall rupture, 20% (2) for ventricular septal rupture, and 73.3% (11) for papillary muscle rupture. These mechanical complications occurred at a median of 23.5 hours (interquartile range 5.0 to 76.8) after symptom onset and were associated with 44% (23 of 52) survival through 90 days, which accounted for 11% of the 90-day mortality. Factors associated with mechanical complications were older age, female gender, Q waves, presence of radiologic pulmonary edema, and increased prerandomization troponin levels. In conclusion, rates of mechanical complications are lower with primary PCI than those previously reported after fibrinolytic therapy

BACKGROUND: The Occluded Artery Trial (OAT) was a 2,201-patient randomized clinical trial comparing routine stent-based percutaneous coronary intervention (PCI) versus optimal medical therapy alone in stable myocardial infarction (MI) survivors with persistent infarct-related artery occlusion identified day 3 to 28 post MI. Intent-to-treat analysis showed no difference between strategies with respect to the incidence of new class IV congestive heart failure, MI, or death. The influence of PCI failure, procedural hazard, and crossover on trial results has not been reported. METHODS: Study angiograms were analyzed and adjudicated centrally. Factors associated with PCI failure were examined. Time-to-event analysis using the OAT primary outcome was performed by PCI success status. Landmark analysis (up to and beyond 30 days) partitioned early hazard versus late outcome according to treatment received. RESULTS: Percutaneous coronary intervention was adjudicated successful in >87%. Percutaneous coronary intervention failure rates were similar in US and non-US sites, and did not significantly influence outcome at 60 months (hazard ratio for success vs fail 0.79, 99% CI 0.45-1.40, P = .29). Partitioning of early procedural hazard revealed no late benefit for PCI (hazard ratio for PCI success vs medical therapy alone 1.06, 99% CI 0.75-1.50, P = .66). CONCLUSIONS: Percutaneous coronary intervention failure and complication rates in the OAT were low. Neither PCI failure nor early procedural hazard substantively influenced the primary trial results