Exhibit 99.40 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-A KEY PERFORMANCE FACTORS July 31, 1999 Expected B Maturity 2/17/2004 Blended Coupon 5.4370% Excess Protection Level 3 Month Average 6.21% July, 1999 5.96% June, 1999 5.11% May, 1999 7.55% Cash Yield18.70% Investor Charge Offs 4.97% Base Rate 7.77% Over 30 Day Delinquency 4.84% Seller's Interest 9.75% Total Payment Rate14.54% Total Principal Balance$45,698,903,036.29 Investor Participation Amount$500,000,000.00 Seller Participation Amount$4,456,383,517.80