In contemporary clinical practice, percutaneous coronary intervention (PCI) is one of the most common methods to treat ischemic heart disease. It has proven to be very effective in appropriately selected patients. However, clinical discretion among interventional clinicians in the absence of definitive evidence-based guidelines results in significant variation in clinical practice of PCI. The objective of this dissertation research is to study the effect of such variation in three aspects on patient outcomes following PCI: (i) post-discharge statin prescription versus no prescription in the setting of otherwise aggressive medical therapy; (ii) use of multiple stents versus a single stent when either approach is clinically feasible; (iii) use versus no use of stent postdilation.
Patients were evaluated from multiple data sources. The first source included the multi-center National Heart, Lung, and Blood Institute (NHLBI) Dynamic registry recruitment Wave 4 (2004) and Wave 5 (2006). For Aim 1 (post-discharge statin vs. no post-discharge statin), patient eligibility criteria included receipt of aspirin, thienopyridines and at least one type of cardiovascular protective medication (angiotensin-converting enzyme inhibitors, Beta blockers, or Calcium channel blockers) after the PCI procedure, and no in-hospital death. Risk of adverse events was compared between post-discharge statin recipients and non-recipients at one-year follow up. Results showed that post-discharge statin use was associated with a reduced risk of mortality and the composite endpoint of death/MI, death/MI/CABG. These data support the routine use of post-PCI statin therapy in the presence of otherwise aggressive medical therapy.
For Aim 2 (multiple versus single stents), the DEScover Registry, a prospective, multicenter, observational study among 140 clinical centers in the United States, was used. The eligibility criteria for this analysis included: receipt of at least one stent for a lesion treated with PCI and the following characteristics: lesion not previously treated; lesion length of 10 to 32mm (i.e. able to be treated with either a single or multiple stents); and an angiographically successful procedure. Survival analysis over 1-year post-PCI showed that patients who received multiple stents had a similar risk of adverse events compared to patients who received a single long stent for each lesion treated. Thus, this analysis was unable to provide definitive evidence for a preference of single versus multiple stents for lesions in the range of 10 to 32 mm.
For Aim 3 (postdilation versus no postdilation), the Dynamic registry recruitment Wave 4 (2004) and Wave 5 (2006) were used. Patient eligibility criteria for this analysis included receipt of greater than or equal to 1 stent and an angiographically successful PCI procedure. Survival analysis over 1-year post-PCI showed that among PCI patients who presented with acute MI, postdilation appears to significantly increase the risk of death by as much as 3-fold. However, because this finding was observed only among patents with one lesion treated but not among patients with multiple lesions treated, the possibility of a chance finding exists. Moreover, among PCI patients who had no acute MI, lesion postdilation did not appear to be associated with either a benefit or increased risk of adverse cardiac events. Thus, this analysis indicated no obvious clinical benefit associated with postdilation in the setting of PCI patients who had no acute MI, and a potential hazardous effect in the setting of acute MI.
Our study has significant public health importance. Heart disease is the leading cause of mortality in nearly every region of the world, accounting for an estimated 30% of all deaths. Coronary heart disease (CHD) is the principal type of heart disease. The public health significance of our study is that investigating the effect of variation in clinical PCI practice can be a benefit to numerous CHD patients all over the world.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-08212007-184732 |
| Date | 27 September 2007 |
| Creators | Zhang, Zhijiang |
| Contributors | Kevin E. Kip, Roslyn A. Stone, Joel L. Weissfeld, Oscar C. Marroquin |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-08212007-184732/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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